CVE-2020-12823

Exp

OpenConnect 8.09 has a buffer overflow, causing a denial of service (application crash) or possibly unspecified other impact, via crafted certificate data to get_cert_name in gnutls.c.

Published: 2020-05-12 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-12823 is rated High Exploit Risk (83.5/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.86%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2020-12823

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-12823

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 2026-01-24 1.51% 1.86% +0.36%
2 2025-11-21 2.42% 1.51% -0.91%
3 2025-11-18 — 2.42% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-12823

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
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:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2020-12823

OS Trackers for CVE-2020-12823

vendor priority summary link
debian unimportant CVE-2020-12823 unimportant priority: Debian including 1 source packages (openconnect), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-12823
gentoo normal CVE-2020-12823: 1 GLSA(s) (202006-15), 1 atom(s) (net-vpn/openconnect); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-12823
suse medium — https://www.suse.com/security/cve/CVE-2020-12823/
ubuntu medium CVE-2020-12823 medium priority: Ubuntu including 1 source packages (openconnect), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 11, needed 3, DNE 1, ignored 1, released 1. https://ubuntu.com/security/CVE-2020-12823

Affected software / configurations for CVE-2020-12823

Vendor Product Version Raw CPE
infradead openconnect 8.09 cpe:2.3:a:infradead:openconnect:8.09:*:*:*:*:*:*:*
fedoraproject fedora 30 cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
fedoraproject fedora 31 cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
opensuse leap 15.2 cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*

References for CVE-2020-12823

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00039.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00056.html Mailing List Third Party Advisory
https://bugs.gentoo.org/721570 Exploit Third Party Advisory
https://gitlab.com/openconnect/openconnect/-/merge_requests/108 Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/05/msg00015.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/25MFX4AZE7RDCUWOL4ZOE73YBOPUMQDX/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AYSXLXAPXD2T73T6JMHI5G2WP7KHAGMN/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BEVTIH5UFX35CC7MVSYBGRM3D66ACFD5/
https://security.gentoo.org/glsa/202006-15 Third Party Advisory
cvelogic Threat Intelligence