High
Security advisory
GnuTLS 3.6.x before 3.6.14 uses incorrect cryptography for encrypting a session ticket (a loss of confidentiality in TLS 1.2, and an authentication bypass in TLS 1.3). The earliest affected version is 3.6.4 (2018-09-24) because of an error in a 2018-09-18 commit. Until the first key rotation, the TLS server always uses wrong data in place of an encryption key derived from an application.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-13777
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 09:42 UTC · Revision 1
Source evidence
GnuTLS 3.6.x before 3.6.14 uses incorrect cryptography for encrypting a session ticket (a loss of confidentiality in TLS 1.2, and an authentication bypass in TLS 1.3). The earliest affected version is 3.6.4 (2018-09-24) because of an error in a 2018-09-18 commit. Until the first key rotation, the TLS server always uses wrong data in place of an encryption key derived from an application.
osv:CVE-2020-13777
Complete source record
{
"id": "bad35d32287d1bca0e585ec2d2fb26f70734a11967eedd4696e70dce998e5b52",
"url": "https://osv.dev/vulnerability/CVE-2020-13777",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-13777",
"summary": "GnuTLS 3.6.x before 3.6.14 uses incorrect cryptography for encrypting a session ticket (a loss of confidentiality in TLS 1.2, and an authentication bypass in TLS 1.3). The earliest affected version is 3.6.4 (2018-09-24) because of an error in a 2018-09-18 commit. Until the first key rotation, the TLS server always uses wrong data in place of an encryption key derived from an application.",
"evidence": "osv:CVE-2020-13777",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2020-13777",
"aliases": [
"CVE-2020-13777"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/gnutls/gnutls",
"type": "GIT",
"events": [
{
"introduced": "b4366978ae5bce1d7ccb5a8751c4f2431517edd4"
},
{
"fixed": "87166be33d6d51ed02dc178e3e6cd64cd5778aad"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:gnu:gnutls:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.6.0"
},
{
"fixed": "3.6.14"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"3.6.14",
"3.6.13",
"gnutls_3_6_12",
"3.6.12",
"gnutls_3_6_11_1",
"gnutls_3_6_11",
"gnutls_3_6_10",
"gnutls_3_6_9",
"gnutls_3_6_7",
"gnutls_3_6_6",
"gnutls_3_6_5",
"gnutls_3_6_4",
"gnutls_3_6_3",
"gnutls_3_6_2",
"gnutls_3_6_1",
"gnutls_3_6_0_1",
"gnutls_3_6_0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-13777.json"
}
},
{
"ranges": [
{
"repo": "https://gitlab.com/gnutls/gnutls",
"type": "GIT",
"events": [
{
"introduced": "b4366978ae5bce1d7ccb5a8751c4f2431517edd4"
},
{
"fixed": "87166be33d6d51ed02dc178e3e6cd64cd5778aad"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:gnu:gnutls:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.6.0"
},
{
"fixed": "3.6.14"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"3.6.14",
"3.6.13",
"gnutls_3_6_12",
"3.6.12",
"gnutls_3_6_11_1",
"gnutls_3_6_11",
"gnutls_3_6_10",
"gnutls_3_6_9",
"gnutls_3_6_7",
"gnutls_3_6_6",
"gnutls_3_6_5",
"gnutls_3_6_4",
"gnutls_3_6_3",
"gnutls_3_6_2",
"gnutls_3_6_1",
"gnutls_3_6_0_1",
"gnutls_3_6_0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-13777.json"
}
}
],
"modified": "2026-10-25T02:45:05.522606817Z",
"provider": "osv",
"references": [
"https://cert-portal.siemens.com/productcert/html/ssa-398330.html",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6C4DHUKV6M6SJ5CV6KVHZNHNF7HCUE5P/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6RTXZOXC4MHTFE2HKY6IAZMF2WHD2WMV/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RRQBFK3UZ7SV76IYDTS4PS6ABS2DSJHK/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VMB3UGI5H5RCFRU6OGRPMNUCNLJGEN7Y/",
"https://gnutls.org/security-new.html#GNUTLS-SA-2020-06-03",
"https://security.gentoo.org/glsa/202006-01",
"https://security.netapp.com/advisory/ntap-20200619-0004/",
"https://usn.ubuntu.com/4384-1/",
"https://www.debian.org/security/2020/dsa-4697"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*",
"cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*"
],
"vendor_product": "canonical:ubuntu_linux",
"extracted_events": [
{
"range": [
{
"introduced": "19.10"
},
{
"last_affected": "19.10"
},
{
"introduced": "20.04"
},
{
"last_affected": "20.04"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*"
],
"vendor_product": "debian:debian_linux",
"extracted_events": [
{
"range": [
{
"introduced": "10.0"
},
{
"last_affected": "10.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "31"
},
{
"last_affected": "31"
},
{
"introduced": "32"
},
{
"last_affected": "32"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2020-13777",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 444578,
"published_at": "2020-06-04T07:15:10+00:00"
}