CVE-2021-20231

The 'GNUTLS_KEYLOGFILE' environment variable in gnutls 3.4.12 allows remote attackers to overwrite and corrupt arbitrary files in the filesystem.

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.

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.

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.

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.

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.

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.

Improper certificate validation in gnutls v3.8.13 causes the application to accept certificates containing invalid extensions.

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.

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.