The verify function in Encryption/Symmetric.php in Malcolm Fell jwt before 1.0.3 does not use a timing-safe function for hash comparison, which allows attackers to spoof signatures via a timing attack.
This category represents one of the phyla in the Seven Pernicious Kingdoms vulnerability classification. It includes weaknesses related to the improper management of time and state in an environment that supports simultaneous or near-simultaneous computation by multiple systems, processes, or threads. According to the authors of the Seven Pernicious Kingdoms, "Distributed computation is about time and state. That is, in order for more than one component to communicate, state must be shared, and all that takes time. Most programmers anthropomorphize their work. They think about one thread of control carrying out the entire program in the same way they would if they had to do the job themselves. Modern computers, however, switch between tasks very quickly, and in multi-core, multi-CPU, or distributed systems, two events may take place at exactly the same time. Defects rush to fill the gap between the programmer's model of how a program executes and what happens in reality. These defects are related to unexpected interactions between threads, processes, time, and information. These interactions happen through shared state: semaphores, variables, the file system, and, basically, anything that can store information."
| Link | Tags |
|---|---|
| https://github.com/emarref/jwt/pull/20 | patch third party advisory issue tracking |
| https://github.com/emarref/jwt/releases/tag/1.0.3 | patch third party advisory issue tracking |
| http://www.securityfocus.com/bid/95847 | vdb entry |