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Privilege Escalation in Rust users crate group listing

IdentifiersCVE-2025-5791CWE-269

CVE-2025-5791 is a privilege escalation flaw in the Rust users crate. According to the provided description, the vulnerability is caused by incorrect group listing logic when a user or process has fewer than exactly 1024 groups. Under that condition, the access list can erroneously include the root group, causing authorization decisions to be made with elevated group membership that was not actually assigned. The issue affects software that relies on the users crate to enumerate supplementary groups and then uses that group list for access-control enforcement.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can cause unauthorized privilege elevation by making a non-root user or process appear to belong to the root group. Any application or service that trusts the affected group enumeration for authorization may incorrectly grant access to privileged resources, administrative functionality, or files restricted to root-group membership.

Mitigation

If you can’t patch tonight, do this now.

Until patched versions are deployed, avoid relying solely on the affected users crate for security-sensitive group-based authorization decisions. Use independent OS-native identity and group verification mechanisms where possible, especially before granting access to privileged resources. Restrict access to applications that perform group-based authorization with this crate, and monitor for anomalous cases where non-root users are treated as members of the root group.

Remediation

Patch, then assume compromise.

Update to a fixed version of the Rust users crate once the vendor-maintained patch is available and rebuild dependent applications against the corrected dependency. Review transitive dependencies to ensure the vulnerable crate version is no longer present. Where feasible, audit authorization logic that depends on group enumeration from this crate to confirm that access checks cannot be influenced by the erroneous root-group inclusion.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

ACTIVITY FEED

Recent activity

11 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.

No news coverage yet. Advisories and community discussion only.

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

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Associated malware

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Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity11

Community discussion across Reddit, Mastodon, and other social sources.