tor/changes/bug40391

10 lines
595 B
Plaintext
Raw Normal View History

o Major bugfixes (security):
- Resist a hashtable-based CPU denial-of-service attack against
relays. Previously we used a naive unkeyed hash function to look up
circuits in a circuitmux object. An attacker could exploit this to
construct circuits with chosen circuit IDs in order to try to create
collisions and make the hash table inefficient. Now we use a SipHash
construction for this hash table instead. Fixes bug 40391; bugfix on
0.2.4.4-alpha. This issue is also tracked as TROVE-2021-005.
Reported by Jann Horn from Google's Project Zero.