CVE-2021-20294

Exp

A flaw was found in binutils readelf 2.35 program. An attacker who is able to convince a victim using readelf to read a crafted file could trigger a stack buffer overflow, out-of-bounds write of arbitrary data supplied by the attacker. The highest impact of this flaw is to confidentiality, integrity, and availability.

Published: 2021-04-29 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20294 is rated High Exploit Risk (71.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.41%). 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-2021-20294

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

Exploit prediction scoring system (EPSS) score for CVE-2021-20294

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 22.71% 3.41% -19.30%
2 2026-04-06 15.86% 22.71% +6.85%
3 2026-03-05 — 15.86% —

Full EPSS history (31 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20294

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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: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.
 1.8 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/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: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:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2021-20294

OS Trackers for CVE-2021-20294

vendor priority summary link
alpine high CVE-2021-20294: 1 source package rows (binutils); 13 state rows across 8 repos (3.10-main, 3.11-main, 3.12-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 0, open 13. https://security.alpinelinux.org/vuln/CVE-2021-20294
debian unimportant CVE-2021-20294 unimportant priority: Debian including 1 source packages (binutils), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-20294
gentoo normal CVE-2021-20294: 1 GLSA(s) (202208-30), 2 atom(s) (sys-devel/binutils, sys-libs/binutils-libs); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-20294
redhat medium — https://access.redhat.com/security/cve/CVE-2021-20294
suse high CVE-2021-20294 severity important: SUSE including 441 source package names (0.23.1-12.3:binutils-2.37-7.26.1, 0.23.1-12.3:libctf-nobfd0-2.37-7.26.1, …), 1397 product×package rows across 319 product lines (Container bci/bci-sle15-kernel-module-devel, Container bci/gcc, … (319 product lines)): Fixed 1139, Known Affected 231, Known Not Affected 27. https://www.suse.com/security/cve/CVE-2021-20294/
ubuntu negligible CVE-2021-20294 negligible priority: Ubuntu including 1 source packages (binutils), 9 status rows across 9 suites (bionic, focal, groovy, hirsute, impish, jammy, trusty, upstream, xenial): not-affected 7, ignored 1, needs-triage 1. https://ubuntu.com/security/CVE-2021-20294

Affected software / configurations for CVE-2021-20294

Vendor Product Version Raw CPE
gnu binutils >= 2.35, < 2.35.2 cpe:2.3:a:gnu:binutils:*:*:*:*:*:*:*:*

References for CVE-2021-20294

cvelogic Threat Intelligence