The DigestAuth server middleware's stale-nonce cleanup uses an inverted comparison: it removes fresh nonces and stops at the first stale one. Because a new nonce is created for every unauthenticated challenge, an attacker can drive the nonce map to grow without bound until the JVM runs out of heap.
Impact
Unauthenticated remote denial of service (gradual heap exhaustion / OOM) against
any service using DigestAuth. The leak is persistent.
Preconditions
- Application uses
DigestAuth on at least one route.
Workarounds
- Front the DigestAuth protected routes with a rate limiter to slow the leak.
- Restart periodically.
Fixes
- The eviction logic is corrected.
- A max cache size of 1000000 is imposed to protected against a burst between evictions. This limit is not yet configurable.
References
rossabaker Analyst
samspills Remediation reviewer
morgen-peschke Remediation reviewer
The
DigestAuthserver middleware's stale-nonce cleanup uses an inverted comparison: it removes fresh nonces and stops at the first stale one. Because a new nonce is created for every unauthenticated challenge, an attacker can drive the nonce map to grow without bound until the JVM runs out of heap.Impact
Unauthenticated remote denial of service (gradual heap exhaustion / OOM) against
any service using DigestAuth. The leak is persistent.
Preconditions
DigestAuthon at least one route.Workarounds
Fixes
References