WCB6200Q: Use of Externally-Controlled Format String
CVE-2024-6145 is a high-severity use of externally-controlled format string vulnerability in WCB6200Q from Actiontec, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected WCB6200Q versions: 1.2L.03.5. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.21% chance of exploitation within 30 days, higher than 69% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of WCB6200Q you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Actiontec | WCB6200Q | 1.2L.03.5 | Not stated |
| Actiontec | wcb6200q_firmware | 1.2l.03.5 | 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
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 3.0 | 8.8 | High | CNA (trendmicro.com) |
Official description
Actiontec WCB6200Q Cookie Format String Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Actiontec WCB6200Q routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the HTTP server. A crafted Cookie header in an HTTP request can trigger the use of a format specifier from a user-supplied string. An attacker can leverage this vulnerability to execute code in the context of the HTTP server. Was ZDI-CAN-21417.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Externally-Controlled Format String
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
How developers prevent this class of flaw
- Choose a language that is not subject to this flaw.
- Ensure that all format string functions are passed a static string which cannot be controlled by the user, and that the proper number of arguments are always sent to that function as well. If at all possible, use functions that do not support the %n operator in format strings.
- Run compilers and linkers with high warning levels, since they may detect incorrect usage.
More Use of Externally-Controlled Format String vulnerabilities (CWE-134)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- zerodayinitiative.com/advisories/ZDI-24-808/Third Party Advisory, VDB Entry
Other vulnerabilities in WCB6200Q
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
Recent Use of Externally-Controlled Format String vulnerabilities
- 9.1 Critical severity
- 7.2 High severity
- 8.8 High severity
- 8.1 High severity
- 9.8 Critical severity
Fortinet Multiple Products Format String Exploited
- 8.8 High severity
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