| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| Issue summary: Calling the OpenSSL API function SSL_select_next_proto with an
empty supported client protocols buffer may cause a crash or memory contents to
be sent to the peer.
Impact summary: A buffer overread can have a range of potential consequences
such as unexpected application beahviour or a crash. In particular this issue
could result in up to 255 bytes of arbitrary private data from memory being sent
to the peer leading to a loss of confidentiality. However, only applications
that directly call the SSL_select_next_proto function with a 0 length list of
supported client protocols are affected by this issue. This would normally never
be a valid scenario and is typically not under attacker control but may occur by
accident in the case of a configuration or programming error in the calling
application.
The OpenSSL API function SSL_select_next_proto is typically used by TLS
applications that support ALPN (Application Layer Protocol Negotiation) or NPN
(Next Protocol Negotiation). NPN is older, was never standardised and
is deprecated in favour of ALPN. We believe that ALPN is significantly more
widely deployed than NPN. The SSL_select_next_proto function accepts a list of
protocols from the server and a list of protocols from the client and returns
the first protocol that appears in the server list that also appears in the
client list. In the case of no overlap between the two lists it returns the
first item in the client list. In either case it will signal whether an overlap
between the two lists was found. In the case where SSL_select_next_proto is
called with a zero length client list it fails to notice this condition and
returns the memory immediately following the client list pointer (and reports
that there was no overlap in the lists).
This function is typically called from a server side application callback for
ALPN or a client side application callback for NPN. In the case of ALPN the list
of protocols supplied by the client is guaranteed by libssl to never be zero in
length. The list of server protocols comes from the application and should never
normally be expected to be of zero length. In this case if the
SSL_select_next_proto function has been called as expected (with the list
supplied by the client passed in the client/client_len parameters), then the
application will not be vulnerable to this issue. If the application has
accidentally been configured with a zero length server list, and has
accidentally passed that zero length server list in the client/client_len
parameters, and has additionally failed to correctly handle a "no overlap"
response (which would normally result in a handshake failure in ALPN) then it
will be vulnerable to this problem.
In the case of NPN, the protocol permits the client to opportunistically select
a protocol when there is no overlap. OpenSSL returns the first client protocol
in the no overlap case in support of this. The list of client protocols comes
from the application and should never normally be expected to be of zero length.
However if the SSL_select_next_proto function is accidentally called with a
client_len of 0 then an invalid memory pointer will be returned instead. If the
application uses this output as the opportunistic protocol then the loss of
confidentiality will occur.
This issue has been assessed as Low severity because applications are most
likely to be vulnerable if they are using NPN instead of ALPN - but NPN is not
widely used. It also requires an application configuration or programming error.
Finally, this issue would not typically be under attacker control making active
exploitation unlikely.
The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.
Due to the low severity of this issue we are not issuing new releases of
OpenSSL at this time. The fix will be included in the next releases when they
become available. |
| Issue summary: Checking excessively long invalid RSA public keys may take
a long time.
Impact summary: Applications that use the function EVP_PKEY_public_check()
to check RSA public keys may experience long delays. Where the key that
is being checked has been obtained from an untrusted source this may lead
to a Denial of Service.
When function EVP_PKEY_public_check() is called on RSA public keys,
a computation is done to confirm that the RSA modulus, n, is composite.
For valid RSA keys, n is a product of two or more large primes and this
computation completes quickly. However, if n is an overly large prime,
then this computation would take a long time.
An application that calls EVP_PKEY_public_check() and supplies an RSA key
obtained from an untrusted source could be vulnerable to a Denial of Service
attack.
The function EVP_PKEY_public_check() is not called from other OpenSSL
functions however it is called from the OpenSSL pkey command line
application. For that reason that application is also vulnerable if used
with the '-pubin' and '-check' options on untrusted data.
The OpenSSL SSL/TLS implementation is not affected by this issue.
The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue. |
| Issue summary: The DTLS retransmission logic does not correctly handle
a handshake message write that is suspended part-way through.
The retransmitted message can be read past the message buffer and
the retransmission overwrites the internal state the suspended write
needs to resume correctly.
Impact summary: The retransmitted message can disclose a heap memory
to the peer as plaintext handshake data or cause a crash and a Denial
of Service when the read reaches an unmapped memory region.
CWE: CWE-125: Out-of-bounds Read
Description: DTLS handshake messages can be written out in multiple
fragments, and a write can suspend mid-message (returning WANT_WRITE)
if the underlying transport temporarily cannot accept more data. While
such a write is suspended, the DTLS retransmission timer may
independently fire and ask the retransmission logic to resend an
earlier, already-acknowledged-as-sent message from its retransmit
queue.
The retransmission logic reused the same internal buffer and position
tracking as the message that was still being written, without
resetting the position back to the start of the message being
retransmitted. As a result the retransmission was read starting from
wherever the suspended write had left off, producing a mislabelled
message whose body was leftover bytes from the other, larger message
still in flight - content that was never meant to be sent at that
point, and which could run past the end of the allocated buffer.
Separately, even when the retransmission is positioned correctly,
allowing it to run to completion while another write is suspended
overwrites the same shared bookkeeping that the suspended write
depends on to resume. When the application later resumes the
suspended write (via a subsequent SSL_read(), SSL_write(),
SSL_accept(), or SSL_connect() call), it finds that bookkeeping in a
state inconsistent with the message and aborts the process in
a debugging build.
The fix resets the retransmission's read position to the start of the
message before resending, and skips retransmission entirely whenever a
handshake write is still suspended, deferring to the next call that
resumes it instead.
FIPS impact: no
The affected code is outside the FIPS module boundary. |
| Issue summary: Calling the OpenSSL API function SSL_free_buffers may cause
memory to be accessed that was previously freed in some situations
Impact summary: A use after free can have a range of potential consequences such
as the corruption of valid data, crashes or execution of arbitrary code.
However, only applications that directly call the SSL_free_buffers function are
affected by this issue. Applications that do not call this function are not
vulnerable. Our investigations indicate that this function is rarely used by
applications.
The SSL_free_buffers function is used to free the internal OpenSSL buffer used
when processing an incoming record from the network. The call is only expected
to succeed if the buffer is not currently in use. However, two scenarios have
been identified where the buffer is freed even when still in use.
The first scenario occurs where a record header has been received from the
network and processed by OpenSSL, but the full record body has not yet arrived.
In this case calling SSL_free_buffers will succeed even though a record has only
been partially processed and the buffer is still in use.
The second scenario occurs where a full record containing application data has
been received and processed by OpenSSL but the application has only read part of
this data. Again a call to SSL_free_buffers will succeed even though the buffer
is still in use.
While these scenarios could occur accidentally during normal operation a
malicious attacker could attempt to engineer a stituation where this occurs.
We are not aware of this issue being actively exploited.
The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue. |
| Issue summary: Checking excessively long DSA keys or parameters may be very
slow.
Impact summary: Applications that use the functions EVP_PKEY_param_check()
or EVP_PKEY_public_check() to check a DSA public key or DSA parameters may
experience long delays. Where the key or parameters that are being checked
have been obtained from an untrusted source this may lead to a Denial of
Service.
The functions EVP_PKEY_param_check() or EVP_PKEY_public_check() perform
various checks on DSA parameters. Some of those computations take a long time
if the modulus (`p` parameter) is too large.
Trying to use a very large modulus is slow and OpenSSL will not allow using
public keys with a modulus which is over 10,000 bits in length for signature
verification. However the key and parameter check functions do not limit
the modulus size when performing the checks.
An application that calls EVP_PKEY_param_check() or EVP_PKEY_public_check()
and supplies a key or parameters obtained from an untrusted source could be
vulnerable to a Denial of Service attack.
These functions are not called by OpenSSL itself on untrusted DSA keys so
only applications that directly call these functions may be vulnerable.
Also vulnerable are the OpenSSL pkey and pkeyparam command line applications
when using the `-check` option.
The OpenSSL SSL/TLS implementation is not affected by this issue.
The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue. |
| Issue summary: Clients using RFC7250 Raw Public Keys (RPKs) to authenticate a
server may fail to notice that the server was not authenticated, because
handshakes don't abort as expected when the SSL_VERIFY_PEER verification mode
is set.
Impact summary: TLS and DTLS connections using raw public keys may be
vulnerable to man-in-middle attacks when server authentication failure is not
detected by clients.
RPKs are disabled by default in both TLS clients and TLS servers. The issue
only arises when TLS clients explicitly enable RPK use by the server, and the
server, likewise, enables sending of an RPK instead of an X.509 certificate
chain. The affected clients are those that then rely on the handshake to
fail when the server's RPK fails to match one of the expected public keys,
by setting the verification mode to SSL_VERIFY_PEER.
Clients that enable server-side raw public keys can still find out that raw
public key verification failed by calling SSL_get_verify_result(), and those
that do, and take appropriate action, are not affected. This issue was
introduced in the initial implementation of RPK support in OpenSSL 3.2.
The FIPS modules in 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected by this issue. |
| Issue summary: Some non-default TLS server configurations can cause unbounded
memory growth when processing TLSv1.3 sessions
Impact summary: An attacker may exploit certain server configurations to trigger
unbounded memory growth that would lead to a Denial of Service
This problem can occur in TLSv1.3 if the non-default SSL_OP_NO_TICKET option is
being used (but not if early_data support is also configured and the default
anti-replay protection is in use). In this case, under certain conditions, the
session cache can get into an incorrect state and it will fail to flush properly
as it fills. The session cache will continue to grow in an unbounded manner. A
malicious client could deliberately create the scenario for this failure to
force a Denial of Service. It may also happen by accident in normal operation.
This issue only affects TLS servers supporting TLSv1.3. It does not affect TLS
clients.
The FIPS modules in 3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL
1.0.2 is also not affected by this issue. |
| A timing-based side-channel flaw exists in the perl-Crypt-OpenSSL-RSA package, which could be sufficient to recover plaintext across a network in a Bleichenbacher-style attack. To achieve successful decryption, an attacker would have to be able to send a large number of trial messages. The vulnerability affects the legacy PKCS#1v1.5 RSA encryption padding mode. |
| A flaw was found in OpenSSL. When configured to use an RSA key with exponent 3, OpenSSL improperly removes PKCS-1 padding before generating a hash. This allows remote attackers to forge PKCS #1 v1.5 signatures. Consequently, OpenSSL may incorrectly verify X.509 and other certificates, leading to a bypass of trust and authentication mechanisms. |
| In addition to the c_rehash shell command injection identified in CVE-2022-1292, further circumstances where the c_rehash script does not properly sanitise shell metacharacters to prevent command injection were found by code review. When the CVE-2022-1292 was fixed it was not discovered that there are other places in the script where the file names of certificates being hashed were possibly passed to a command executed through the shell. This script is distributed by some operating systems in a manner where it is automatically executed. On such operating systems, an attacker could execute arbitrary commands with the privileges of the script. Use of the c_rehash script is considered obsolete and should be replaced by the OpenSSL rehash command line tool. Fixed in OpenSSL 3.0.4 (Affected 3.0.0,3.0.1,3.0.2,3.0.3). Fixed in OpenSSL 1.1.1p (Affected 1.1.1-1.1.1o). Fixed in OpenSSL 1.0.2zf (Affected 1.0.2-1.0.2ze). |
| The c_rehash script does not properly sanitise shell metacharacters to prevent command injection. This script is distributed by some operating systems in a manner where it is automatically executed. On such operating systems, an attacker could execute arbitrary commands with the privileges of the script. Use of the c_rehash script is considered obsolete and should be replaced by the OpenSSL rehash command line tool. Fixed in OpenSSL 3.0.3 (Affected 3.0.0,3.0.1,3.0.2). Fixed in OpenSSL 1.1.1o (Affected 1.1.1-1.1.1n). Fixed in OpenSSL 1.0.2ze (Affected 1.0.2-1.0.2zd). |
| ChaCha20-Poly1305 is an AEAD cipher, and requires a unique nonce input for every encryption operation. RFC 7539 specifies that the nonce value (IV) should be 96 bits (12 bytes). OpenSSL allows a variable nonce length and front pads the nonce with 0 bytes if it is less than 12 bytes. However it also incorrectly allows a nonce to be set of up to 16 bytes. In this case only the last 12 bytes are significant and any additional leading bytes are ignored. It is a requirement of using this cipher that nonce values are unique. Messages encrypted using a reused nonce value are susceptible to serious confidentiality and integrity attacks. If an application changes the default nonce length to be longer than 12 bytes and then makes a change to the leading bytes of the nonce expecting the new value to be a new unique nonce then such an application could inadvertently encrypt messages with a reused nonce. Additionally the ignored bytes in a long nonce are not covered by the integrity guarantee of this cipher. Any application that relies on the integrity of these ignored leading bytes of a long nonce may be further affected. Any OpenSSL internal use of this cipher, including in SSL/TLS, is safe because no such use sets such a long nonce value. However user applications that use this cipher directly and set a non-default nonce length to be longer than 12 bytes may be vulnerable. OpenSSL versions 1.1.1 and 1.1.0 are affected by this issue. Due to the limited scope of affected deployments this has been assessed as low severity and therefore we are not creating new releases at this time. Fixed in OpenSSL 1.1.1c (Affected 1.1.1-1.1.1b). Fixed in OpenSSL 1.1.0k (Affected 1.1.0-1.1.0j). |
| The OpenSSL RSA Key generation algorithm has been shown to be vulnerable to a cache timing side channel attack. An attacker with sufficient access to mount cache timing attacks during the RSA key generation process could recover the private key. Fixed in OpenSSL 1.1.0i-dev (Affected 1.1.0-1.1.0h). Fixed in OpenSSL 1.0.2p-dev (Affected 1.0.2b-1.0.2o). |
| Issue summary: Checking excessively long DH keys or parameters may be very slow.
Impact summary: Applications that use the functions DH_check(), DH_check_ex()
or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long
delays. Where the key or parameters that are being checked have been obtained
from an untrusted source this may lead to a Denial of Service.
The function DH_check() performs various checks on DH parameters. After fixing
CVE-2023-3446 it was discovered that a large q parameter value can also trigger
an overly long computation during some of these checks. A correct q value,
if present, cannot be larger than the modulus p parameter, thus it is
unnecessary to perform these checks if q is larger than p.
An application that calls DH_check() and supplies a key or parameters obtained
from an untrusted source could be vulnerable to a Denial of Service attack.
The function DH_check() is itself called by a number of other OpenSSL functions.
An application calling any of those other functions may similarly be affected.
The other functions affected by this are DH_check_ex() and
EVP_PKEY_param_check().
Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications
when using the "-check" option.
The OpenSSL SSL/TLS implementation is not affected by this issue.
The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue. |
| The ssl3_get_key_exchange function in s3_clnt.c in OpenSSL before 0.9.8zd, 1.0.0 before 1.0.0p, and 1.0.1 before 1.0.1k allows remote SSL servers to conduct RSA-to-EXPORT_RSA downgrade attacks and facilitate brute-force decryption by offering a weak ephemeral RSA key in a noncompliant role, related to the "FREAK" issue. NOTE: the scope of this CVE is only client code based on OpenSSL, not EXPORT_RSA issues associated with servers or other TLS implementations. |
| Issue summary: Checking excessively long DH keys or parameters may be very slow.
Impact summary: Applications that use the functions DH_check(), DH_check_ex()
or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long
delays. Where the key or parameters that are being checked have been obtained
from an untrusted source this may lead to a Denial of Service.
The function DH_check() performs various checks on DH parameters. One of those
checks confirms that the modulus ('p' parameter) is not too large. Trying to use
a very large modulus is slow and OpenSSL will not normally use a modulus which
is over 10,000 bits in length.
However the DH_check() function checks numerous aspects of the key or parameters
that have been supplied. Some of those checks use the supplied modulus value
even if it has already been found to be too large.
An application that calls DH_check() and supplies a key or parameters obtained
from an untrusted source could be vulernable to a Denial of Service attack.
The function DH_check() is itself called by a number of other OpenSSL functions.
An application calling any of those other functions may similarly be affected.
The other functions affected by this are DH_check_ex() and
EVP_PKEY_param_check().
Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications
when using the '-check' option.
The OpenSSL SSL/TLS implementation is not affected by this issue.
The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue. |
| Issue summary: Processing some specially crafted ASN.1 object identifiers or
data containing them may be very slow.
Impact summary: Applications that use OBJ_obj2txt() directly, or use any of
the OpenSSL subsystems OCSP, PKCS7/SMIME, CMS, CMP/CRMF or TS with no message
size limit may experience notable to very long delays when processing those
messages, which may lead to a Denial of Service.
An OBJECT IDENTIFIER is composed of a series of numbers - sub-identifiers -
most of which have no size limit. OBJ_obj2txt() may be used to translate
an ASN.1 OBJECT IDENTIFIER given in DER encoding form (using the OpenSSL
type ASN1_OBJECT) to its canonical numeric text form, which are the
sub-identifiers of the OBJECT IDENTIFIER in decimal form, separated by
periods.
When one of the sub-identifiers in the OBJECT IDENTIFIER is very large
(these are sizes that are seen as absurdly large, taking up tens or hundreds
of KiBs), the translation to a decimal number in text may take a very long
time. The time complexity is O(n^2) with 'n' being the size of the
sub-identifiers in bytes (*).
With OpenSSL 3.0, support to fetch cryptographic algorithms using names /
identifiers in string form was introduced. This includes using OBJECT
IDENTIFIERs in canonical numeric text form as identifiers for fetching
algorithms.
Such OBJECT IDENTIFIERs may be received through the ASN.1 structure
AlgorithmIdentifier, which is commonly used in multiple protocols to specify
what cryptographic algorithm should be used to sign or verify, encrypt or
decrypt, or digest passed data.
Applications that call OBJ_obj2txt() directly with untrusted data are
affected, with any version of OpenSSL. If the use is for the mere purpose
of display, the severity is considered low.
In OpenSSL 3.0 and newer, this affects the subsystems OCSP, PKCS7/SMIME,
CMS, CMP/CRMF or TS. It also impacts anything that processes X.509
certificates, including simple things like verifying its signature.
The impact on TLS is relatively low, because all versions of OpenSSL have a
100KiB limit on the peer's certificate chain. Additionally, this only
impacts clients, or servers that have explicitly enabled client
authentication.
In OpenSSL 1.1.1 and 1.0.2, this only affects displaying diverse objects,
such as X.509 certificates. This is assumed to not happen in such a way
that it would cause a Denial of Service, so these versions are considered
not affected by this issue in such a way that it would be cause for concern,
and the severity is therefore considered low. |
| The function X509_VERIFY_PARAM_add0_policy() is documented to
implicitly enable the certificate policy check when doing certificate
verification. However the implementation of the function does not
enable the check which allows certificates with invalid or incorrect
policies to pass the certificate verification.
As suddenly enabling the policy check could break existing deployments it was
decided to keep the existing behavior of the X509_VERIFY_PARAM_add0_policy()
function.
Instead the applications that require OpenSSL to perform certificate
policy check need to use X509_VERIFY_PARAM_set1_policies() or explicitly
enable the policy check by calling X509_VERIFY_PARAM_set_flags() with
the X509_V_FLAG_POLICY_CHECK flag argument.
Certificate policy checks are disabled by default in OpenSSL and are not
commonly used by applications. |
| Applications that use a non-default option when verifying certificates may be
vulnerable to an attack from a malicious CA to circumvent certain checks.
Invalid certificate policies in leaf certificates are silently ignored by
OpenSSL and other certificate policy checks are skipped for that certificate.
A malicious CA could use this to deliberately assert invalid certificate policies
in order to circumvent policy checking on the certificate altogether.
Policy processing is disabled by default but can be enabled by passing
the `-policy' argument to the command line utilities or by calling the
`X509_VERIFY_PARAM_set1_policies()' function. |
| A security vulnerability has been identified in all supported versions
of OpenSSL related to the verification of X.509 certificate chains
that include policy constraints. Attackers may be able to exploit this
vulnerability by creating a malicious certificate chain that triggers
exponential use of computational resources, leading to a denial-of-service
(DoS) attack on affected systems.
Policy processing is disabled by default but can be enabled by passing
the `-policy' argument to the command line utilities or by calling the
`X509_VERIFY_PARAM_set1_policies()' function. |
