A heap-based buffer overflow vulnerability in SIPp allows unauthenticated remote attackers to cause a denial of service by sending specifically crafted SIP packets.

The vulnerability resides in the get_header() function within src/sip_parser.cpp, where the application fails to properly validate the size of incoming SIP header content. An unauthenticated remote attacker can supply header content exceeding 20,490 bytes, triggering a buffer overflow that crashes the application process.

Successful exploitation of this vulnerability results in a denial of service for the affected SIPp instance. Given that SIPp is frequently used for performance testing and stress testing of telecommunications infrastructure, an unexpected process crash can lead to significant testing downtime, loss of test data, and potential disruption to workflows reliant on the availability of the SIPp tool. The CVSS score of 7.5 reflects the high impact on availability, even though the vulnerability does not currently facilitate remote code execution or data theft.

Immediate Action: Organizations should restrict network access to SIPp instances to trusted administrative networks and monitor for potential vendor patches to address the overflow in the get_header() function.

Proactive Monitoring: Security teams should monitor system logs and process status for unexpected terminations or segmentation faults in the sipp executable.

Compensating Controls: Deploy a network-level firewall or session border controller to inspect and drop malformed or oversized SIP packets before they reach the SIPp instance.

Public Exploit Available: No

The vulnerability presents a clear risk to service availability for those utilizing SIPp in exposed environments. While no patch is currently identified, administrators must prioritize network segmentation and packet filtering to prevent unauthorized actors from reaching the vulnerable parsing logic. Once a vendor update becomes available, it should be applied as part of the standard patch management cycle to fully remediate the underlying buffer handling flaw.