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Public proof of conceptFix available

CVE-2021-43317

A public proof of concept exists; no exploitation attested.

  • Published2023-03-24
  • Fixed in4.0.0
  • WeaknessCWE-119 · CWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A heap-based buffer overflows was discovered in upx, during the generic pointer 'p' points to an inaccessible address in func get_le32(). The problem is essentially caused in PackLinuxElf64::elf_lookup() at p_lx_elf.cpp:5404

Timeline

dates in UTC
  1. 2023-03-2420:15CVE publishedNVD

Versions per branch

NVD
Upx
BranchAffectedFixed in
4.0< 4.0.04.0.0

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As fedora, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • upx
    Affected
    • = upx before 4.0.0-git-c6b9e3c62d15no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2023-03-24

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • upxSUSE:Package Hub 15 SP4all versions · fixed in 4.0.2-bp154.4.6.1
  • upxopenSUSE:Leap 15.4all versions · fixed in 4.0.2-bp154.4.6.1
  • upx-uclUbuntu:26.10all versions · no fixed version listed
  • upx-uclUbuntu:26.04:LTSall versions · no fixed version listed
  • upx-uclUbuntu:25.10all versions · no fixed version listed
  • upx-uclUbuntu:24.04:LTSall versions · no fixed version listed
  • upx-uclUbuntu:22.04:LTSall versions · no fixed version listed
  • upx-uclUbuntu:20.04:LTSall versions · no fixed version listed

4 more package ranges on OSV.dev

Vendor advisories

  • CVE-2021-43317 Red Hat Product Security

    upx: heap-based buffer overflow in PackLinuxElf64::elf_lookup() at p_lx_elf.cpp

Full record on NVD

Fix

  1. Update Upx to 4.0.0

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2023-03-24
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-fg24-8xq8-v4pp

Frequently asked questions

What is CVE-2021-43317?

A heap-based buffer overflows was discovered in upx, during the generic pointer 'p' points to an inaccessible address in func get_le32(). The problem is essentially caused in PackLinuxElf64::elf_lookup() at p_lx_elf.cpp:5404

Is CVE-2021-43317 actively exploited?

A proof-of-concept exploit exists for CVE-2021-43317, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2021-43317?

CVE-2021-43317 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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Sources for this record