CVE-2020-11501

GnuTLS 3.6.x before 3.6.13 uses incorrect cryptography for DTLS. The earliest affected version is 3.6.3 (2018-07-16) because of an error in a 2017-10-06 commit. The DTLS client always uses 32 '\0' bytes instead of a random value, and thus contributes no randomness to a DTLS negotiation. This breaks the security guarantees of the DTLS protocol.

Published: 2020-04-03 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-11501 is rated Moderate Risk (55.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.39%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-11501

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 11.49% 3.39% -8.10%
2 2025-11-21 3.34% 11.49% +8.14%
3 2025-11-18 — 3.34% —

Full EPSS history (21 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-11501

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.4 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 5.2 [email protected]
5.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 4.9 [email protected]

Weakness enumeration for CVE-2020-11501

OS Trackers for CVE-2020-11501

vendor priority summary link
alpine high CVE-2020-11501: 1 source package rows (gnutls); 14 state rows across 9 repos (3.10-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 9, open 5. https://security.alpinelinux.org/vuln/CVE-2020-11501
debian not yet assigned CVE-2020-11501 not yet assigned priority: Debian including 1 source packages (gnutls28), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-11501
redhat medium — https://access.redhat.com/security/cve/CVE-2020-11501
suse high CVE-2020-11501 severity important: SUSE including 750 source package names (0.0.17-1.1:libgmp10-6.1.2-4.3.1, 0.1.0:libgmp10-6.1.2-4.3.1, …), 1482 product×package rows across 620 product lines (Container bci/bci-base-fips, Container bci/bci-init, … (620 product lines)): Fixed 1257, Known Affected 157, Known Not Affected 68. https://www.suse.com/security/cve/CVE-2020-11501/
ubuntu medium CVE-2020-11501 medium priority: Ubuntu including 1 source packages (gnutls28), 5 status rows across 5 suites (bionic, eoan, trusty, upstream, xenial): not-affected 2, released 2, DNE 1. https://ubuntu.com/security/CVE-2020-11501

Affected software / configurations for CVE-2020-11501

Vendor Product Version Raw CPE
gnu gnutls >= 3.6.3, < 3.6.13 cpe:2.3:a:gnu:gnutls:*:*:*:*:*:*:*:*
canonical ubuntu_linux 19.10 cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
fedoraproject fedora 31 cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*

References for CVE-2020-11501

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00015.html Third Party Advisory
https://gitlab.com/gnutls/gnutls/-/commit/5b595e8e52653f6c5726a4cdd8fddeb6e83804d2 Patch Third Party Advisory
https://gitlab.com/gnutls/gnutls/-/issues/960 Issue Tracking Patch Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ILMOWPKMTZAIMK5F32TUMO34XCABUCFJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WDYY3R4F5CUTFAMXH2C5NKYFVDEJLTT7/
https://security.gentoo.org/glsa/202004-06 Third Party Advisory
https://security.netapp.com/advisory/ntap-20200416-0002/ Third Party Advisory
https://usn.ubuntu.com/4322-1/ Third Party Advisory
https://www.debian.org/security/2020/dsa-4652 Third Party Advisory
https://www.gnutls.org/security-new.html#GNUTLS-SA-2020-03-31 Vendor Advisory
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