CVE-2021-33453

Exp

An issue was discovered in lrzip version 0.641. There is a use-after-free in ucompthread() in stream.c:1538.

Published: 2022-07-26 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-33453 is rated Exploit Available (51.6/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). 2 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-2021-33453

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

Exploit prediction scoring system (EPSS) score for CVE-2021-33453

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 0.08% 0.05% -0.03%
2 2025-07-27 0.03% 0.08% +0.04%
3 2025-03-30 — 0.03% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-33453

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]

Weakness enumeration for CVE-2021-33453

OS Trackers for CVE-2021-33453

vendor priority summary link
debian unimportant CVE-2021-33453 unimportant priority: Debian including 1 source packages (lrzip), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2021-33453
ubuntu medium CVE-2021-33453 medium priority: Ubuntu including 1 source packages (lrzip), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): needs-triage 8, ignored 5. https://ubuntu.com/security/CVE-2021-33453

Affected software / configurations for CVE-2021-33453

Vendor Product Version Raw CPE
long_range_zip_project long_range_zip 0.641 cpe:2.3:a:long_range_zip_project:long_range_zip:0.641:*:*:*:*:*:*:*

References for CVE-2021-33453

URL Tags
https://gist.github.com/Clingto/bb632c0c463f4b2c97e4f65f751c5e6d Exploit Third Party Advisory
https://github.com/ckolivas/lrzip/issues/199 Exploit Issue Tracking Third Party Advisory
cvelogic Threat Intelligence