Vulnerability · CVE-2020-13777
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).
Published Jun 4, 2020 · catalog updated Oct 14, 2026 · GnuTLS 3.6.x before 3.6.14
Check this week
CVE-2020-13777 is not in CISA KEV. FIRST estimates a 22.28% chance of exploitation in the next 30 days. Check whether you run GnuTLS 3.6.x before 3.6.14.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (GnuTLS 3.6.x before 3.6.14).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High7.4
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 22.28%
- Remediation
- Advisory link
- Affected products
- cpe canonical/ubuntu linux · cpe debian/debian linux · cpe fedoraproject/fedora · cpe gnu/gnutls
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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe canonical/ubuntu linux19.10
- cpe canonical/ubuntu linux20.04
- cpe debian/debian linux10.0
- cpe fedoraproject/fedora31
- cpe fedoraproject/fedora32
- cpe gnu/gnutlsversion unspecified
How to fix CVE-2020-13777
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
CVE-2020-13777 is not in CISA KEV. FIRST estimates a 22.28% chance of exploitation in the next 30 days. Check whether you run GnuTLS 3.6.x before 3.6.14.
Which versions are affected?
Compare what you have installed with canonical/ubuntu linux 19.10; canonical/ubuntu linux 20.04; debian/debian linux 10.0. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-327: Use of a Broken or Risky Cryptographic Algorithm. EPSS 22.28%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Jun 4, 2020 · NIST NVD
Detected
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.
Oct 14, 2026 · NIST NVD
Updated
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.
Sources
- CVE.orgVulnerability recordCVE-2020-13777
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2020-13777
30-day exploitation probability 22.3%
first.org - NIST NVDVulnerability recordCVE-2020-13777
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
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 16, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.