GnuTLS before 3.1.0 does not verify that the RSA PKCS #1 signature algorithm matches the signature algorithm in the certificate, which allows remote attackers to conduct downgrade attacks via unspecified vectors.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Gnutls | Gnu | * | 3.0.9 (including) |
| Red Hat Enterprise Linux 6 | RedHat | gnutls-0:2.8.5-18.el6 | * |
| Gnutls26 | Ubuntu | esm-infra-legacy/trusty | * |
| Gnutls26 | Ubuntu | lucid | * |
| Gnutls26 | Ubuntu | precise | * |
| Gnutls26 | Ubuntu | trusty | * |
| Gnutls26 | Ubuntu | trusty/esm | * |
| Gnutls26 | Ubuntu | upstream | * |
| Gnutls26 | Ubuntu | utopic | * |
| Gnutls28 | Ubuntu | precise | * |
| Gnutls28 | Ubuntu | upstream | * |