Wrt54gl Firmware: Improper Neutralization of Special Elements used in a Command
CVE-2023-31742 is a high-severity improper neutralization of special elements used in a command vulnerability in Wrt54gl Firmware from Linksys, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected Wrt54gl Firmware versions: 4.30.18.006. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 9.15% chance of exploitation within 30 days, which is in the top 4.6% of all scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Wrt54gl Firmware you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linksys | Wrt54gl Firmware | 4.30.18.006 | Not stated |
Version data comes from NVD's product matching. 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.
- Privileges required
- HighAdministrator-level access is required first.
- 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:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.2 | High | NVD |
| CVSS 3.1 | 7.2 | High | CISA (ADP) |
Official description
There is a command injection vulnerability in the Linksys WRT54GL router with firmware version 4.30.18.006. If an attacker gains web management privileges, they can inject commands into the post request parameters wl_ant, wl_rate, WL_atten_ctl, ttcp_num, ttcp_size in the httpd s Start_EPI() function, thereby gaining shell privileges.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in a Command
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- If possible, ensure that all external commands called from the program are statically created.
- Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.
More Improper Neutralization of Special Elements used in a Command vulnerabilities (CWE-77)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/D2y6p/CVE/blob/main/Linksys/CVE-2023-31742/Linksys_WRT54GL_RCE.pdfExploit, Mitigation, Third Party Advisory
Other vulnerabilities in Wrt54gl Firmware
- 7.5 High severity
- 7.2 High severity
- 7.5 High severity
- 7.2 High severity
Recent Improper Neutralization of Special Elements used in a Command vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
- 9.8 Critical severity
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