PJSIP is a free and open source multimedia communication library written in the C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In various parts of PJSIP, when error/failure occurs, it is found that the function returns without releasing the currently held locks. This could result in a system deadlock, which cause a denial of service for the users. No release has yet been made which contains the linked fix commit. All versions up to an including 2.11.1 are affected. Users may need to manually apply the patch.
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Pjsip | Teluu | * | 2.11.1 (including) |
| Ring | Ubuntu | bionic | * |
| Ring | Ubuntu | hirsute | * |
| Ring | Ubuntu | impish | * |
| Ring | Ubuntu | lunar | * |
| Ring | Ubuntu | mantic | * |
| Ring | Ubuntu | trusty | * |
| Ring | Ubuntu | xenial | * |
Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.