Openssl: >> Openssl >> 1.0.2d Security Vulnerabilities
Issue summary: During processing of a crafted CMS EnvelopedData message
with KeyAgreeRecipientInfo a NULL pointer dereference can happen.
Impact summary: Applications that process attacker-controlled CMS data may
crash before authentication or cryptographic operations occur resulting in
Denial of Service.
When a CMS EnvelopedData message that uses KeyAgreeRecipientInfo is
processed, the optional parameters field of KeyEncryptionAlgorithmIdentifier
is examined without checking for its presence. This results in a NULL
pointer dereference if the field is missing.
Applications and services that call CMS_decrypt() on untrusted input
(e.g., S/MIME processing or CMS-based protocols) are vulnerable.
The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this
issue, as the affected code is outside the OpenSSL FIPS module boundary.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-04-07
Issue summary: During processing of a crafted CMS EnvelopedData message
with KeyTransportRecipientInfo a NULL pointer dereference can happen.
Impact summary: Applications that process attacker-controlled CMS data may
crash before authentication or cryptographic operations occur resulting in
Denial of Service.
When a CMS EnvelopedData message that uses KeyTransportRecipientInfo with
RSA-OAEP encryption is processed, the optional parameters field of
RSA-OAEP SourceFunc algorithm identifier is examined without checking
for its presence. This results in a NULL pointer dereference if the field
is missing.
Applications and services that call CMS_decrypt() on untrusted input
(e.g., S/MIME processing or CMS-based protocols) are vulnerable.
The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this
issue, as the affected code is outside the OpenSSL FIPS module boundary.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-04-07
Issue summary: When a delta CRL that contains a Delta CRL Indicator extension
is processed a NULL pointer dereference might happen if the required CRL
Number extension is missing.
Impact summary: A NULL pointer dereference can trigger a crash which
leads to a Denial of Service for an application.
When CRL processing and delta CRL processing is enabled during X.509
certificate verification, the delta CRL processing does not check
whether the CRL Number extension is NULL before dereferencing it.
When a malformed delta CRL file is being processed, this parameter
can be NULL, causing a NULL pointer dereference.
Exploiting this issue requires the X509_V_FLAG_USE_DELTAS flag to be enabled in
the verification context, the certificate being verified to contain a
freshestCRL extension or the base CRL to have the EXFLAG_FRESHEST flag set, and
an attacker to provide a malformed CRL to an application that processes it.
The vulnerability is limited to Denial of Service and cannot be escalated to
achieve code execution or memory disclosure. For that reason the issue was
assessed as Low severity according to our Security Policy.
The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue,
as the affected code is outside the OpenSSL FIPS module boundary.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-04-07
Issue summary: A type confusion vulnerability exists in the signature
verification of signed PKCS#7 data where an ASN1_TYPE union member is
accessed without first validating the type, causing an invalid or NULL
pointer dereference when processing malformed PKCS#7 data.
Impact summary: An application performing signature verification of PKCS#7
data or calling directly the PKCS7_digest_from_attributes() function can be
caused to dereference an invalid or NULL pointer when reading, resulting in
a Denial of Service.
The function PKCS7_digest_from_attributes() accesses the message digest attribute
value without validating its type. When the type is not V_ASN1_OCTET_STRING,
this results in accessing invalid memory through the ASN1_TYPE union, causing
a crash.
Exploiting this vulnerability requires an attacker to provide a malformed
signed PKCS#7 to an application that verifies it. The impact of the
exploit is just a Denial of Service, the PKCS7 API is legacy and applications
should be using the CMS API instead. For these reasons the issue was
assessed as Low severity.
The FIPS modules in 3.5, 3.4, 3.3 and 3.0 are not affected by this issue,
as the PKCS#7 parsing implementation is outside the OpenSSL FIPS module
boundary.
OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue.
CVSS Score
5.3
EPSS Score
0.005
Published
2026-01-27
Issue summary: Processing a malformed PKCS#12 file can trigger a NULL pointer
dereference in the PKCS12_item_decrypt_d2i_ex() function.
Impact summary: A NULL pointer dereference can trigger a crash which leads to
Denial of Service for an application processing PKCS#12 files.
The PKCS12_item_decrypt_d2i_ex() function does not check whether the oct
parameter is NULL before dereferencing it. When called from
PKCS12_unpack_p7encdata() with a malformed PKCS#12 file, this parameter can
be NULL, causing a crash. The vulnerability is limited to Denial of Service
and cannot be escalated to achieve code execution or memory disclosure.
Exploiting this issue requires an attacker to provide a malformed PKCS#12 file
to an application that processes it. For that reason the issue was assessed as
Low severity according to our Security Policy.
The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue,
as the PKCS#12 implementation is outside the OpenSSL FIPS module boundary.
OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-01-27
Issue summary: Writing large, newline-free data into a BIO chain using the
line-buffering filter where the next BIO performs short writes can trigger
a heap-based out-of-bounds write.
Impact summary: This out-of-bounds write can cause memory corruption which
typically results in a crash, leading to Denial of Service for an application.
The line-buffering BIO filter (BIO_f_linebuffer) is not used by default in
TLS/SSL data paths. In OpenSSL command-line applications, it is typically
only pushed onto stdout/stderr on VMS systems. Third-party applications that
explicitly use this filter with a BIO chain that can short-write and that
write large, newline-free data influenced by an attacker would be affected.
However, the circumstances where this could happen are unlikely to be under
attacker control, and BIO_f_linebuffer is unlikely to be handling non-curated
data controlled by an attacker. For that reason the issue was assessed as
Low severity.
The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue,
as the BIO implementation is outside the OpenSSL FIPS module boundary.
OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue.
CVSS Score
4.7
EPSS Score
0.0
Published
2026-01-27
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 will
be vulnerable to this issue.
OpenSSL APIs that are vulnerable to this are: PKCS12_parse(),
PKCS12_unpack_p7data(), PKCS12_unpack_p7encdata(), PKCS12_unpack_authsafes()
and PKCS12_newpass().
We have also fixed a similar issue in SMIME_write_PKCS7(). However since this
function is related to writing data we do not consider it security significant.
The FIPS modules in 3.2, 3.1 and 3.0 are not affected by this issue.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-01-26
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_check_pub_key() doesn't make any of these checks, and is therefore
vulnerable for excessively large P and Q parameters.
Likewise, while DH_generate_key() performs a check for an excessively large
P, it doesn't check for an excessively large Q.
An application that calls DH_generate_key() or DH_check_pub_key() and
supplies a key or parameters obtained from an untrusted source could be
vulnerable to a Denial of Service attack.
DH_generate_key() and DH_check_pub_key() are also 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_pub_key_ex(), EVP_PKEY_public_check(), and EVP_PKEY_generate().
Also vulnerable are the OpenSSL pkey command line application when using the
"-pubcheck" option, as well as the OpenSSL genpkey command line application.
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.
CVSS Score
5.3
EPSS Score
0.005
Published
2023-11-06
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.
CVSS Score
5.3
EPSS Score
0.003
Published
2023-07-31
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.
CVSS Score
6.5
EPSS Score
0.917
Published
2023-05-30
Page 1