CVE-2020-20902

A CWE-125: Out-of-bounds read vulnerability exists in long_term_filter function in g729postfilter.c in FFmpeg 4.2.1 during computation of the denominator of pseudo-normalized correlation R'(0), that could result in disclosure of information.

Published: 2021-09-20 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-20902 is rated Moderate Risk (48.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.13%). 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-2020-20902

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 0.40% 1.13% +0.73%
2 2026-06-09 0.46% 0.40% -0.06%
3 2026-05-24 — 0.46% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-20902

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/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: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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/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:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2020-20902

OS Trackers for CVE-2020-20902

vendor priority summary link
alpine medium CVE-2020-20902: 1 source package rows (ffmpeg); 2 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 2. https://security.alpinelinux.org/vuln/CVE-2020-20902
debian not yet assigned CVE-2020-20902 not yet assigned priority: Debian including 1 source packages (ffmpeg), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-20902
suse medium CVE-2020-20902 severity moderate: SUSE including 57 source package names (ffmpeg-3.4.2-11.17.1, ffmpeg-private-devel-3.4.2-11.17.1, …), 501 product×package rows across 35 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 6, … (35 product lines)): Fixed 501. https://www.suse.com/security/cve/CVE-2020-20902/
ubuntu low CVE-2020-20902 low priority: Ubuntu including 2 source packages (ffmpeg, qtwebengine-opensource-src), 30 status rows across 15 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 18, ignored 8, DNE 2, released 2. https://ubuntu.com/security/CVE-2020-20902

Affected software / configurations for CVE-2020-20902

Vendor Product Version Raw CPE
ffmpeg ffmpeg 4.2.1 cpe:2.3:a:ffmpeg:ffmpeg:4.2.1:*:*:*:*:*:*:*

References for CVE-2020-20902

cvelogic Threat Intelligence