ConfigServer Security & Firewall: Files or Directories Accessible to External Parties
CVE-2026-67402 is a critical-severity files or directories accessible to external parties vulnerability in ConfigServer Security & Firewall from WebPros, with a CVSS 4.0 base score of 9.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 16.31 as the first without the flaw, so updating ConfigServer Security & Firewall to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.54% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update ConfigServer Security & Firewall to 16.31 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| WebPros | ConfigServer Security & Firewall | 14.02 up to, but not including, 16.31 | 16.31 |
| ConfigServer | ConfigServer Security & Firewall | 14.02 and later | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- PresentThe target must be in a specific state or configuration for the attack to work.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- LowLimited loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- LowLimited loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/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:X/V:X/RE:X/U:X. Scored by CNA (hackerone.com).
Official description
An insecure Apache configuration in ConfigServer Security & Firewall maps /usr/bin as CGI programs through the Messenger v3 HTTPS virtual host. A remote unauthenticated attacker whose address is blocked can request a mapped executable and run arbitrary commands as the Apache user. The vulnerability affects installations where CSF Messenger v3 and its HTTPS mode are enabled. WebPros addressed the vulnerability in version 16.31.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Files or Directories Accessible to External Parties
The product makes files or directories accessible to unauthorized actors, even though they should not be.
How developers prevent this class of flaw
- When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to disable public access.
More Files or Directories Accessible to External Parties vulnerabilities (CWE-552)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in ConfigServer Security & Firewall
- 9.5 Critical severity
- 9.2 Critical severity
Recent Files or Directories Accessible to External Parties vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 7.7 High severity
- 7.7 High severity
- 8.1 High severity
- 8.1 High severity
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