CVE-2021-20232
CriticalCVSS 9.8Exploitation Probability (EPSS)
High risk89th percentile - higher than 89% of all known CVEs
Summary
A flaw was found in gnutls. A use-after-free issue in client_send_params in lib/ext/pre_shared_key.c may lead to memory corruption and other potential consequences.
Risk Assessment
Exploitation may result in memory corruption, service crashes, or potentially arbitrary code execution in applications using gnutls.
Recommendation
Update gnutls to a version containing the fix for this issue.
Other vulnerabilities in GnuTLS
See all- CVE-2016-4456High
The 'GNUTLS_KEYLOGFILE' environment variable in gnutls 3.4.12 allows remote attackers to overwrite and corrupt arbitrary files in the filesystem.
- CVE-2017-7507High
GnuTLS version 3.5.12 and earlier is vulnerable to a NULL pointer dereference while decoding a status response TLS extension with valid contents. This could lead to a crash of the GnuTLS server application.
- CVE-2017-7869High
GnuTLS before February 20, 2017, has an out-of-bounds write caused by an integer overflow and heap-based buffer overflow related to the cdk_pkt_read function in opencdk/read-packet.c. This issue is a subset of the vendor's GNUTLS-SA-2017-3 report and is fixed in version 3.5.10.
- CVE-2017-5335High
The stream reading functions in lib/opencdk/read-packet.c in GnuTLS before 3.3.26 and 3.5.x before 3.5.8 allow remote attackers to cause a denial of service (out-of-memory error and crash) via a crafted OpenPGP certificate.
- CVE-2016-7444High
The gnutls_ocsp_resp_check_crt function in GnuTLS before 3.4.15 and 3.5.x before 3.5.4 does not verify the serial length of an OCSP response, which might allow remote attackers to bypass an intended certificate validation mechanism.
- CVE-2015-3308High
A double free vulnerability in lib/x509/x509_ext.c in GnuTLS before version 3.3.14 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted CRL distribution point.
- CVE-2024-28834Medium
A flaw was found in GnuTLS related to the Minerva attack, a cryptographic vulnerability that exploits deterministic behavior, leading to side-channel leaks. In specific scenarios, such as using the GNUTLS_PRIVKEY_FLAG_REPRODUCIBLE flag, it can result in a noticeable step in nonce values.
- CVE-2026-95210Critical
Improper certificate validation in gnutls v3.8.13 causes the application to accept certificates containing invalid extensions.
- CVE-2026-88647Critical
A hostname verification bypass in GnuTLS v3.8.13 allows attackers to circumvent the Common Name fallback mechanism and eavesdrop on communications via a crafted certificate.
- CVE-2021-20231Critical
A flaw was found in gnutls. A use after free issue in client sending key_share extension may lead to memory corruption and other consequences.
Original NVD description (English source)
A flaw was found in gnutls. A use after free issue in client_send_params in lib/ext/pre_shared_key.c may lead to memory corruption and other potential consequences.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS