← Vulnerability feed

Vulnerability record · CVE-2026-100713 · published 26 September 2026

CVE-2026-100713: TOCTOU race condition vulnerability

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.

7.1 CVSS 4.0 High CWE-367 · TOCTOU race condition Deferred
7.1CVSS 4.0 base score
—EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
2References
26 Sep 2026Last modified by NVD

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.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

References

LinkTags
https://github.com/froxlor/froxlor/security/advisories/GHSA-927x-9jfh-mq42
https://www.vulncheck.com/advisories/froxlor-before-2.3.12-privilege-escalation-via-ssh-key-sync

Track CVE-2026-100713 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

5.1CVE-2015-3246libuser userhelper direct /etc/passwd write race conditionlibuser before 0.56.13-8 and 0.60 before 0.60-7, as used by the userhelper program in the usermode package, modifies /etc/passwd directly instead of …KEVEPSS 8.8%analysed7.8CVE-2025-38352Linux kernel POSIX CPU timer TOCTOU race enables local privilege escalationA time-of-check to time-of-use race exists in the Linux kernel between handle_posix_cpu_timers() and posix_cpu_timer_del(). When an exiting non-autor…KEVEPSS 1.3%analysed8.2CVE-2025-22224VMware ESXi and Workstation TOCTOU race leads to out-of-bounds writeVMware ESXi, Workstation, and related products contain a TOCTOU race condition that results in an out-of-bounds write. An attacker with local adminis…KEVEPSS 1.6%analysed7.0CVE-2024-30088Windows Kernel TOCTOU race condition privilege escalationCVE-2024-30088 is a time-of-check time-of-use (TOCTOU) race condition in the Windows kernel that allows a local user to elevate privileges. It affect…KEVEPSS 68%analysed7.0CVE-2022-48618Apple OS Pointer Authentication Bypass via TOCTOU Race ConditionA time-of-check time-of-use race condition in Apple's pointer authentication implementation allows an attacker who already holds arbitrary read and w…KEVEPSS 0.49%analysed8.8CVE-2023-35311Microsoft Outlook security feature bypass via TOCTOU race conditionCVE-2023-35311 is a security feature bypass in Microsoft Outlook caused by a time-of-check time-of-use (TOCTOU) race condition (CWE-367). It affects …KEVEPSS 16%analysed

Source: NIST National Vulnerability Database (record CVE-2026-100713), CISA KEV, FIRST EPSS. This page is refreshed as NVD updates the record.