Executive brief
SIPp is a widely-used open-source SIP (Session Initiation Protocol) testing and traffic generation tool. An unauthenticated remote attacker can send a specially crafted SIP message with oversized header content to crash the SIPp process, causing a denial of service to any systems relying on SIPp for call simulation or testing.
Technical details
A stack-based buffer overflow exists in the get_header() function in src/sip_parser.cpp when processing SIP messages with headers exceeding 20,490 bytes. The vulnerable code uses a fixed-size static buffer without proper bounds checking. An unauthenticated remote attacker on the network can send a crafted SIP message with an oversized header to overflow this buffer, crashing the SIPp process. This is a network-reachable, pre-authentication vulnerability; no user interaction or authentication is required. The primary impact is denial of service through process termination.
Affected products
- SIPp SIPp through 3.7.7
Timeline
- 2026-09-13: disclosed