Openssl: >> Openssl >> 1.1.1i Security Vulnerabilities
Issue summary: An invalid or NULL pointer dereference can happen in
an application processing a malformed PKCS#12 file.
Impact summary: An application processing a malformed PKCS#12 file can be
caused to dereference an invalid or NULL pointer on memory read, resulting
in a Denial of Service.
A type confusion vulnerability exists in PKCS#12 parsing code where
an ASN1_TYPE union member is accessed without first validating the type,
causing an invalid pointer read.
The location is constrained to a 1-byte address space, meaning any
attempted pointer manipulation can only target addresses between 0x00 and 0xFF.
This range corresponds to the zero page, which is unmapped on most modern
operating systems and will reliably result in a crash, leading only to a
Denial of Service. Exploiting this issue also requires a user or application
to process a maliciously crafted PKCS#12 file. It is uncommon to accept
untrusted PKCS#12 files in applications as they are usually used to store
private keys which are trusted by definition. 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 PKCS12 implementation is outside the OpenSSL FIPS module boundary.
OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are vulnerable to this issue.
OpenSSL 1.0.2 is not affected by this issue.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-27
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: Calling PKCS12_get_friendlyname() function on a maliciously
crafted PKCS#12 file with a BMPString (UTF-16BE) friendly name containing
non-ASCII BMP code point can trigger a one byte write before the allocated
buffer.
Impact summary: The out-of-bounds write can cause a memory corruption
which can have various consequences including a Denial of Service.
The OPENSSL_uni2utf8() function performs a two-pass conversion of a PKCS#12
BMPString (UTF-16BE) to UTF-8. In the second pass, when emitting UTF-8 bytes,
the helper function bmp_to_utf8() incorrectly forwards the remaining UTF-16
source byte count as the destination buffer capacity to UTF8_putc(). For BMP
code points above U+07FF, UTF-8 requires three bytes, but the forwarded
capacity can be just two bytes. UTF8_putc() then returns -1, and this negative
value is added to the output length without validation, causing the
length to become negative. The subsequent trailing NUL byte is then written
at a negative offset, causing write outside of heap allocated buffer.
The vulnerability is reachable via the public PKCS12_get_friendlyname() API
when parsing attacker-controlled PKCS#12 files. While PKCS12_parse() uses a
different code path that avoids this issue, PKCS12_get_friendlyname() directly
invokes the vulnerable function. Exploitation requires an attacker to provide
a malicious PKCS#12 file to be parsed by the application and the attacker
can just trigger a one zero byte write before the allocated buffer.
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 and 1.1.1 are vulnerable to this issue.
OpenSSL 1.0.2 is not affected by this issue.
CVSS Score
7.4
EPSS Score
0.001
Published
2026-01-27
Issue summary: A type confusion vulnerability exists in the TimeStamp Response
verification code where an ASN1_TYPE union member is accessed without first
validating the type, causing an invalid or NULL pointer dereference when
processing a malformed TimeStamp Response file.
Impact summary: An application calling TS_RESP_verify_response() with a
malformed TimeStamp Response can be caused to dereference an invalid or
NULL pointer when reading, resulting in a Denial of Service.
The functions ossl_ess_get_signing_cert() and ossl_ess_get_signing_cert_v2()
access the signing cert attribute value without validating its type.
When the type is not V_ASN1_SEQUENCE, this results in accessing invalid memory
through the ASN1_TYPE union, causing a crash.
Exploiting this vulnerability requires an attacker to provide a malformed
TimeStamp Response to an application that verifies timestamp responses. The
TimeStamp protocol (RFC 3161) is not widely used and the impact of the
exploit is just a Denial of Service. 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 TimeStamp Response implementation is outside the OpenSSL FIPS module
boundary.
OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are vulnerable to this issue.
OpenSSL 1.0.2 is not affected by this issue.
CVSS Score
7.5
EPSS Score
0.003
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: When using the low-level OCB API directly with AES-NI or<br>other hardware-accelerated code paths, inputs whose length is not a multiple<br>of 16 bytes can leave the final partial block unencrypted and unauthenticated.<br><br>Impact summary: The trailing 1-15 bytes of a message may be exposed in<br>cleartext on encryption and are not covered by the authentication tag,<br>allowing an attacker to read or tamper with those bytes without detection.<br><br>The low-level OCB encrypt and decrypt routines in the hardware-accelerated<br>stream path process full 16-byte blocks but do not advance the input/output<br>pointers. The subsequent tail-handling code then operates on the original<br>base pointers, effectively reprocessing the beginning of the buffer while<br>leaving the actual trailing bytes unprocessed. The authentication checksum<br>also excludes the true tail bytes.<br><br>However, typical OpenSSL consumers using EVP are not affected because the<br>higher-level EVP and provider OCB implementations split inputs so that full<br>blocks and trailing partial blocks are processed in separate calls, avoiding<br>the problematic code path. Additionally, TLS does not use OCB ciphersuites.<br>The vulnerability only affects applications that call the low-level<br>CRYPTO_ocb128_encrypt() or CRYPTO_ocb128_decrypt() functions directly with<br>non-block-aligned lengths in a single call on hardware-accelerated builds.<br>For these reasons the issue was assessed as Low severity.<br><br>The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected<br>by this issue, as OCB mode is not a FIPS-approved algorithm.<br><br>OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are vulnerable to this issue.<br><br>OpenSSL 1.0.2 is not affected by this issue.
CVSS Score
4.0
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
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 calculating the MAC of data larger than 64 bytes. Before returning to
the caller all the XMM registers are set to zero rather than restoring their
previous content. The vulnerable code is used only on newer x86_64 processors
supporting the AVX512-IFMA instructions.
The consequences of this kind of internal application state corruption can
be various - from no consequences, if the calling application does not
depend on the contents of non-volatile XMM registers at all, to the worst
consequences, where the attacker could get complete control of the application
process. However given the contents of the registers are just zeroized so
the attacker cannot put arbitrary values inside, the most likely consequence,
if any, would be an incorrect result of some application dependent
calculations or a crash leading to a denial of service.
The POLY1305 MAC algorithm is most frequently used as part of the
CHACHA20-POLY1305 AEAD (authenticated encryption with associated data)
algorithm. The most common usage of this AEAD cipher is with TLS protocol
versions 1.2 and 1.3 and a malicious client can influence whether this AEAD
cipher is used by the server. This implies that server applications using
OpenSSL can be potentially impacted. However we are currently not aware of
any concrete application that would be affected by this issue therefore we
consider this a Low severity security issue.
As a workaround the AVX512-IFMA instructions support can be disabled at
runtime by setting the environment variable OPENSSL_ia32cap:
OPENSSL_ia32cap=:~0x200000
The FIPS provider is not affected by this issue.
CVSS Score
7.8
EPSS Score
0.008
Published
2023-09-08
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