CVE-2025-58151
varstored: TOCTOU issues with mapped guest memory
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
varstored is a component of the Xapi toolstack handling UEFI Variables for a VM. It has a communication path with OVMF inside the VM involving mapping a buffer prepared by OVMF. Within varstored, there were insufficient compiler barriers, creating TOCTOU issues with data in the shared buffer. The exact vulnerable behaviour depends on the code generated by the compiler. In a build of varstored using default settings, the attacker can control an index used in a jump table.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Xen varstored
All versions