Security readout for executives and security teams
Plain-English summary
UPX 3.95 can crash when handling certain Linux ELF data because of a floating-point exception. The known impact is denial of service to the UPX process, not data theft or system takeover based on the provided sources.
Executive priority
Treat as targeted availability risk for teams or services that process binaries. Prioritize remediation if UPX runs automatically on submitted or third-party ELF files.
Technical view
The flaw is in PackLinuxElf::elf_hash in p_lx_elf.cpp in UPX 3.95. Processing a malformed or unexpected ELF input can trigger a floating-point exception and terminate the application, causing availability impact.
Likely exposure
Exposure is most likely where UPX 3.95 is installed or embedded in automated workflows that process Linux ELF files, especially untrusted binaries.
Exploitation context
The source bundle does not show CISA KEV listing or cited active exploitation. Public issue tracking exists, but the provided evidence supports crash-based denial of service only.
Researcher notes
Evidence is limited to the CVE description, upstream GitHub issue, and Fedora advisories. No CVSS, CWE, exploit confirmation, or specific fixed version is provided in the bundle.
Mitigation direction
- Inventory systems and build pipelines for UPX 3.95 usage.
- Apply vendor or distribution UPX updates where available.
- Review Fedora advisories if using Fedora-packaged UPX.
- Avoid processing untrusted ELF files with vulnerable UPX versions.
- Isolate binary processing jobs to limit operational disruption.
Validation and detection
- Confirm installed UPX versions across developer, CI, and analysis systems.
- Check whether automated services pass untrusted ELF files to UPX.
- Review crash logs for UPX floating-point exceptions.
- Verify vendor package advisories are applied on Fedora systems.
- Test remediation in a non-production binary-processing workflow.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2019-20051 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/upx/upx/issues/313CVE reference · x_refsource_MISC
- FEDORA-2020-20cf0743f5CVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2020-67590fbf08CVE reference · vendor-advisory, x_refsource_FEDORA
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.