The vulnerability is a null pointer dereference in the ims_client SIP module. When the sipuri.c utility processes SIP URIs, it performs a null check but then dereferences a pointer that may be null. According to CWE‑476, this can cause the process to crash or exhibit unexpected behavior, which could lead to denial of service or other integrity impacts if an attacker can control the malformed input.

This flaw affects ASR1903 devices running ASR Lapwing Linux firmware versions that include the ims_client sipuri.c code. The affected component resides in the sip/utils src. Exact firmware versions are not listed, so all current releases containing that source file are potentially vulnerable.

With a CVSS score of 7.4 the vulnerability is considered high severity. The EPSS score is not available, and the flaw is not yet listed in the CISA KEV catalog, indicating it may not be actively exploited at this time. The attack vector is inferred to be locally exploitable via the IMS client; an attacker would need to feed malformed SIP URIs to trigger the null dereference. Administrators should treat the risk as significant pending a vendor fix.