Openssl: >> Openssl >> 1.0.2zi Security Vulnerabilities
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
0.001
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
0.0
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
0.006
Published
2023-11-06
mutt_ssl.c in mutt 1.5.19 and 1.5.20, when OpenSSL is used, does not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.
CVSS Score
6.8
EPSS Score
0.006
Published
2009-10-23
mutt_ssl.c in mutt 1.5.16 and other versions before 1.5.19, when OpenSSL is used, does not verify the domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.
CVSS Score
6.8
EPSS Score
0.005
Published
2009-10-23
libraries/libldap/tls_o.c in OpenLDAP 2.2 and 2.4, and possibly other versions, when OpenSSL is used, does not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.
CVSS Score
4.3
EPSS Score
0.018
Published
2009-10-23
Mutt 1.5.19, when linked against (1) OpenSSL (mutt_ssl.c) or (2) GnuTLS (mutt_ssl_gnutls.c), allows connections when only one TLS certificate in the chain is accepted instead of verifying the entire chain, which allows remote attackers to spoof trusted servers via a man-in-the-middle attack.
CVSS Score
6.8
EPSS Score
0.004
Published
2009-06-16