CVE-2021-46179

Reachable Assertion vulnerability in upx before 4.0.0 allows attackers to cause a denial of service via crafted file passed to the the readx function.

Published: 2023-08-22 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-46179 is rated Low Risk (38.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.45%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2021-46179

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 0.10% 0.45% +0.35%
2 2025-11-21 0.21% 0.10% -0.10%
3 2025-11-18 — 0.21% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-46179

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:N/I:N/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: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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]

Weakness enumeration for CVE-2021-46179

OS Trackers for CVE-2021-46179

vendor priority summary link
alpine medium CVE-2021-46179: 1 source package rows (upx); 5 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 5. https://security.alpinelinux.org/vuln/CVE-2021-46179
debian unimportant CVE-2021-46179 unimportant priority: Debian including 1 source packages (upx-ucl), 4 status rows across 4 suites (bullseye, forky, sid, trixie): resolved 3, open 1. https://security-tracker.debian.org/tracker/CVE-2021-46179
ubuntu medium CVE-2021-46179 medium priority: Ubuntu including 1 source packages (upx-ucl), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): needs-triage 7, ignored 5. https://ubuntu.com/security/CVE-2021-46179

Affected software / configurations for CVE-2021-46179

Vendor Product Version Raw CPE
upx upx < 4.0.0 cpe:2.3:a:upx:upx:*:*:*:*:*:*:*:*

References for CVE-2021-46179

URL Tags
https://github.com/upx/upx/issues/545 Issue Tracking Patch
cvelogic Threat Intelligence