CVE-2024-39943: hfs · Improper Access Control
Affects hfsSource CVE Database V5
Not known to be exploited · 39% EPSS · CVSS 9.9 Critical : upgrade to 0.52.10 as a priority.
Data as of 26 Oct 2026, 09:08 UTC
- EPSS
- 39.4% chance of exploitation in 30 days – higher than 98% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.52.10
CVSS:3.1/AC:L/AV:N/A:H/C:H/I:H/PR:L/S:C/UI:NExploitation evidence
Disclosed: evidence found.
CVE published 4 Jul 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade rejetto/hfs to 0.52.10.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubrejetto/hfspkg:github/rejetto/hfsOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
To mitigate CVE-2024-39943, organizations should immediately upgrade rejetto HFS to version 0.52.10 or later, where the vulnerability is fixed by replacing execSync with spawnSync to safely execute system commands. If patching is not immediately possible, restrict Upload permissions to only fully trusted users and audit existing permissions to minimize exposure. Implement strict input validation and sanitization on any user-supplied data that might be used in command execution contexts. Employ network segmentation and firewall rules to limit access to HFS servers, especially from untrusted networks. Monitor logs for unusual command execution patterns or unauthorized uploads. Consider deploying application-layer firewalls or runtime application self-protection (RASP) solutions to detect and block command injection attempts. Regularly review and update authentication mechanisms to ensure strong, multi-factor authentication is enforced for users with upload rights. Finally, conduct security awareness training for administrators and users about the risks of granting upload permissions and the importance of applying security patches promptly.
Description
rejetto HFS (aka HTTP File Server) 3 before 0.52.10 on Linux, UNIX, and macOS allows OS command execution by remote authenticated users (if they have Upload permissions). This occurs because a shell is used to execute df (i.e., with execSync instead of spawnSync in child_process in Node.js).