Froxlor before 2.3.12 Privilege Escalation via SSH Key Sync

Description

Froxlor 2.3.10 and earlier contain a time-of-check time-of-use (TOCTOU) race condition in the SSH key synchronization cron (lib/Froxlor/Cron/System/SshKeys.php, SshKeys::generateFiles). The containment/symlink validation performed by FileDir::makeCorrectDir()/makeCorrectFile() is done only at check time; the live filesystem path is re-resolved as root at write time (file_put_contents with FILE_APPEND|LOCK_EX, followed by chmod/chown/chgrp), with a database round-trip and file reads in between, and no path or file-descriptor pinning (no O_NOFOLLOW or openat2(RESOLVE_NO_SYMLINKS)). On installations where the non-default setting system.allow_customer_shell=1 grants customers local shell access, a customer can atomically swap their ~/.ssh directory for a symlink after the check and before the write, causing the root-run cron to append the customer's public key to /root/.ssh/authorized_keys and to chown /root/.ssh to the customer, resulting in full root compromise of the panel host. The cron re-runs on every interval, allowing unlimited attempts. This is a residual race that bypasses the check-time fix introduced for GHSA-mq5v-... . The issue is fixed in Froxlor 2.3.12.

Scores

EPSS (exploitation in 30 days)

0.16% · top 95% of all CVEs (4 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: total

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.

Weakness

• CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition (opens in a new tab)All about CWE-367 and its CVEs

Affected products

• froxlor · froxlor

  • affected < 2.3.12
  • unaffected 2.3.12

References (2)

• GitHub Security Advisory (GHSA-927x-9jfh-mq42) (opens in a new tab)vendor-advisory
• VulnCheck Advisory: Froxlor before 2.3.12 Privilege Escalation via SSH Key Sync (opens in a new tab)third-party-advisory

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-100713](https://trackcve.app/badge/CVE-2026-100713.svg)](https://trackcve.app/cve/CVE-2026-100713)

Record last updated 26 Sept 2026, 23:10 UTC.