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No exploitation reportedFix available

CVE-2021-30500

No exploitation reported by the sources we read.

  • Published2021-05-27
  • WeaknessCWE-476

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

Null pointer dereference was found in upx PackLinuxElf::canUnpack() in p_lx_elf.cpp,in version UPX 4.0.0. That allow attackers to execute arbitrary code and cause a denial of service via a crafted file.

Timeline

dates in UTC
  1. 2021-05-2700:15CVE publishedNVD

Versions per branch

NVD
Upx
BranchAffectedFixed in
4.0= 4.0.0no fix published
Fedoraproject fedora
BranchAffectedFixed in
33.x= 33no fix published
Redhat enterprise linux
BranchAffectedFixed in
7.0= 7.0no fix published

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

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
  • upxCleanStartall versions · fixed in 4.0.0-r0
  • upxAlpine:v3.24all versions · fixed in 4.0.0-r0
  • upxAlpine:v3.23all versions · fixed in 4.0.0-r0
  • upxAlpine:v3.22all versions · fixed in 4.0.0-r0
  • upxAlpine:v3.21all versions · fixed in 4.0.0-r0
  • upxAlpine:v3.20all versions · fixed in 4.0.0-r0

13 more package ranges on OSV.dev

Vendor advisories

  • CVE-2021-30500 Red Hat Product Security

    upx: Null pointer dereference in PackLinuxElf::canUnpack() in p_lx_elf.cpp

Full record on NVD

Fix

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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published
2021-05-27
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-5339-45c2-mh5v

Frequently asked questions

What is CVE-2021-30500?

Null pointer dereference was found in upx PackLinuxElf::canUnpack() in p_lx_elf.cpp,in version UPX 4.0.0. That allow attackers to execute arbitrary code and cause a denial of service via a crafted file.

Is CVE-2021-30500 actively exploited?

Active exploitation of CVE-2021-30500 has not been confirmed. Its EPSS score was 1.2% on 2026-11-09, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-30500?

CVE-2021-30500 has a CVSS v3 base score of 7.8 (HIGH severity), with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

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Sources for this record