Security readout for executives and security teams
Plain-English summary
CVE-2020-27790 is a UPX crash bug triggered by a crafted input file. The documented impact is denial of service: UPX can crash while handling certain 64-bit Linux ELF content. Sources do not show code execution, data theft, or confirmed active exploitation.
Executive priority
Treat this as a targeted availability risk for teams or services that run UPX on untrusted binaries. Prioritize remediation in automated analysis or pipeline contexts, but it is not presented as a broad remote compromise issue.
Technical view
The issue is a floating point exception in UPX's PackLinuxElf64::invert_pt_dynamic() function in p_lx_elf.cpp, classified as CWE-369. A crafted file can trigger a crash. The source bundle identifies the fix as UPX v3.96.
Likely exposure
Exposure is most likely where UPX processes untrusted or externally supplied Linux ELF64 files, especially in malware analysis, CI, unpacking, or file-inspection workflows. General systems not running UPX on untrusted files are less exposed.
Exploitation context
The public sources describe crafted-input denial of service. The CVE is not listed as KEV in the bundle, and no cited source supports active exploitation. Evidence is limited to the CVE description, GitHub issue, and fix commit.
Researcher notes
Key gaps: no CVSS score is provided, affected pre-fix version ranges are not fully enumerated, and exploitation is not confirmed. The strongest source-grounded fix statement is that the issue was fixed in UPX v3.96.
Mitigation direction
- Upgrade UPX to v3.96 or later where used.
- Avoid processing untrusted files with vulnerable UPX versions.
- Run UPX file handling in isolated, resource-limited environments.
- Check vendor and project guidance for any later advisories.
Validation and detection
- Inventory UPX versions across developer, CI, and analysis systems.
- Confirm installed UPX versions are v3.96 or later.
- Identify workflows that pass untrusted ELF64 files to UPX.
- Review crash logs for UPX failures tied to malformed inputs.
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.
CWE-369: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2020-27790 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/331CVE reference · x_refsource_MISC
- https://github.com/upx/upx/commit/eb90eab6325d009004ffb155e3e33f22d4d3ca26CVE reference · x_refsource_MISC
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.
Divide By Zero
Divide By Zero represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.