Unbounded memory growth with session handling in TLSv1.3
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 unb
Issue summary: Processing a maliciously formatted PKCS12 file may lead OpenSSL
to crash leading to a potential Denial of Service attack
Impact summary: Applications loading files in the PKCS12 format from untrusted
sources might terminate abruptly.
A file in PKCS12 format can contain certificates and keys and may come from an
untrusted source. The PKCS12 specification allows certain fields to be NULL, but
OpenSSL does not correctly check for this case. This can lead to a NULL pointer
dereference that results in OpenSSL crashing. If an application processes PKCS12
files from an untrusted source using the OpenSSL APIs then that application wi
POLY1305 MAC implementation corrupts vector registers on PowerPC
Issue summary: The POLY1305 MAC (message authentication code) implementation
contains a bug that might corrupt the internal state of applications running
on PowerPC CPU based platforms if the CPU provides vector instructions.
Impact summary: If an attacker can influence whether the POLY1305 MAC
algorithm is used, the application state might be corrupted with various
application dependent consequences.
The POLY1305 MAC (message authentication code) implementation in OpenSSL for
PowerPC CPUs restores the contents of vector registers in a different order
than they are saved. Thus the contents of some of these vector registers
are corrupted whe
Excessive time spent in DH check / generation with large Q parameter value
Issue summary: Generating excessively long X9.42 DH keys or checking
excessively long X9.42 DH keys or parameters may be very slow.
Impact summary: Applications that use the functions DH_generate_key() to
generate an X9.42 DH key may experience long delays. Likewise, applications
that use DH_check_pub_key(), DH_check_pub_key_ex() or EVP_PKEY_public_check()
to check an X9.42 DH key or X9.42 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.
While DH_check() performs all the necessary checks (as of CVE-2023-3817),
DH_ch
Issue summary: A bug has been identified in the processing of key and
initialisation vector (IV) lengths. This can lead to potential truncation
or overruns during the initialisation of some symmetric ciphers.
Impact summary: A truncation in the IV can result in non-uniqueness,
which could result in loss of confidentiality for some cipher modes.
When calling EVP_EncryptInit_ex2(), EVP_DecryptInit_ex2() or
EVP_CipherInit_ex2() the provided OSSL_PARAM array is processed after
the key and IV have been established. Any alterations to the key length,
via the "keylen" parameter or the IV length, via the "ivlen" parameter,
within the OSSL_PARAM a
POLY1305 MAC implementation corrupts XMM registers on Windows
Issue summary: The POLY1305 MAC (message authentication code) implementation
contains a bug that might corrupt the internal state of applications on the
Windows 64 platform when running on newer X86_64 processors supporting the
AVX512-IFMA instructions.
Impact summary: If in an application that uses the OpenSSL library an attacker
can influence whether the POLY1305 MAC algorithm is used, the application
state might be corrupted with various application dependent consequences.
The POLY1305 MAC (message authentication code) implementation in OpenSSL does
not save the contents of non-volatile XMM registers on Windows 64 platform
when calculati
Excessive time spent checking DH q parameter value
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
Excessive time spent checking DH keys and parameters
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 lengt
AES-SIV implementation ignores empty associated data entries
Issue summary: The AES-SIV cipher implementation contains a bug that causes
it to ignore empty associated data entries which are unauthenticated as
a consequence.
Impact summary: Applications that use the AES-SIV algorithm and want to
authenticate empty data entries as associated data can be misled by removing,
adding or reordering such empty entries as these are ignored by the OpenSSL
implementation. We are currently unaware of any such applications.
The AES-SIV algorithm allows for authentication of multiple associated
data entries along with the encryption. To authenticate empty data the
application has to call EVP_EncryptUpdate() (or EV
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 canon
Input buffer over-read in AES-XTS implementation on 64 bit ARM
Issue summary: The AES-XTS cipher decryption implementation for 64 bit ARM
platform contains a bug that could cause it to read past the input buffer,
leading to a crash.
Impact summary: Applications that use the AES-XTS algorithm on the 64 bit ARM
platform can crash in rare circumstances. The AES-XTS algorithm is usually
used for disk encryption.
The AES-XTS cipher decryption implementation for 64 bit ARM platform will read
past the end of the ciphertext buffer if the ciphertext size is 4 mod 5 in 16
byte blocks, e.g. 144 bytes or 1024 bytes. If the memory after the ciphertext
buffer is unmapped, this will trigger a crash which results in a
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
Invalid certificate policies in leaf certificates are silently ignored
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.
A read buffer overrun can be triggered in X.509 certificate verification,
specifically in name constraint checking. Note that this occurs
after certificate chain signature verification and requires either a
CA to have signed the malicious certificate or for the application to
continue certificate verification despite failure to construct a path
to a trusted issuer.
The read buffer overrun might result in a crash which could lead to
a denial of service attack. In theory it could also result in the disclosure
of private memory contents (such as private keys, or sensitive plaintext)
although we are not aware of any working exploit leading to me
A timing based side channel exists in the OpenSSL RSA Decryption implementation
which could be sufficient to recover a plaintext across a network in a
Bleichenbacher style attack. To achieve a successful decryption an attacker
would have to be able to send a very large number of trial messages for
decryption. The vulnerability affects all RSA padding modes: PKCS#1 v1.5,
RSA-OEAP and RSASVE.
For example, in a TLS connection, RSA is commonly used by a client to send an
encrypted pre-master secret to the server. An attacker that had observed a
genuine connection between a client and a server could use this flaw to send
trial messages to the ser
The function PEM_read_bio_ex() reads a PEM file from a BIO and parses and
decodes the "name" (e.g. "CERTIFICATE"), any header data and the payload data.
If the function succeeds then the "name_out", "header" and "data" arguments are
populated with pointers to buffers containing the relevant decoded data. The
caller is responsible for freeing those buffers. It is possible to construct a
PEM file that results in 0 bytes of payload data. In this case PEM_read_bio_ex()
will return a failure code but will populate the header argument with a pointer
to a buffer that has already been freed. If the caller also frees this buffer
then a double free wil
The public API function BIO_new_NDEF is a helper function used for streaming
ASN.1 data via a BIO. It is primarily used internally to OpenSSL to support the
SMIME, CMS and PKCS7 streaming capabilities, but may also be called directly by
end user applications.
The function receives a BIO from the caller, prepends a new BIO_f_asn1 filter
BIO onto the front of it to form a BIO chain, and then returns the new head of
the BIO chain to the caller. Under certain conditions, for example if a CMS
recipient public key is invalid, the new filter BIO is freed and the function
returns a NULL result indicating a failure. However, in this case, the BIO cha
Invalid pointer dereference in d2i_PKCS7 functions
An invalid pointer dereference on read can be triggered when an
application tries to load malformed PKCS7 data with the
d2i_PKCS7(), d2i_PKCS7_bio() or d2i_PKCS7_fp() functions.
The result of the dereference is an application crash which could
lead to a denial of service attack. The TLS implementation in OpenSSL
does not call this function however third party applications might
call these functions on untrusted data.
An invalid pointer dereference on read can be triggered when an
application tries to check a malformed DSA public key by the
EVP_PKEY_public_check() function. This will most likely lead
to an application crash. This function can be called on public
keys supplied from untrusted sources which could allow an attacker
to cause a denial of service attack.
The TLS implementation in OpenSSL does not call this function
but applications might call the function if there are additional
security requirements imposed by standards such as FIPS 140-3.