CVE-2022-43972 — A null pointer dereference vulnerability exists in Linksys WRT54GL Wireless-G Br

A null pointer dereference vulnerability exists in Linksys WRT54GL Wireless-G Broadband Router with firmware <= 4.30.18.006. A null pointer dereference in the soap_action function within the upnp binary can be triggered by an unauthenticated attacker via a malicious POST reque

01What is this vulnerability?

A null pointer dereference vulnerability exists in Linksys WRT54GL Wireless-G Broadband Router with firmware <= 4.30.18.006. A null pointer dereference in the soap_action function within the upnp binary can be triggered by an unauthenticated attacker via a malicious POST request invoking the AddPortMapping action.

02Affected products

Vendor	Product	Versions
Linksys	WRT54GL Wireless	G Broadband Router — Firmware

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-01-09T00:00:00.000Z
• Last modified: 2025-04-09T14:22:24.605Z

09References

• youtu.be — https://youtu.be/73-1lhvJPNg
• youtu.be — https://youtu.be/TeWAmZaKQ_w
• youtu.be — https://youtu.be/RfWVYCUBNZ0