The Redis protocol implementation in Apache bRPC allowed inline command parsing to allocate and…

Why it is Amber

• CVSS 7.5 high
• Remotely exploitable without logging in
• On your watchlist: redis

References

• https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb

Original description

The Redis protocol implementation in Apache bRPC allowed inline command parsing to allocate and copy the full connection buffer before a complete CRLF-terminated command was available. A remote attacker with access to a Redis-protocol bRPC service could send long inline inputs without a terminating CRLF to increase memory usage and CPU copy overhead, potentially causing denial of service. Root Cause: The Redis inline command parser allocated memory based on the current input buffer size and copied the entire buffer before determining the current inline command boundary. The existing redis_max_allocation_size limit was applied to RESP bulk strings and arrays, but not effectively to the inline command path before allocation. Affected Scenarios: Use Apache bRPC server with Redis protocol enabled and reachable by untrusted clients. How to Fix: 1. Upgrade Apache bRPC to version 1.18.0, which fixes this issue. 2. Apply the patch from PR https://github.com/apache/brpc/pull/3363 . Note: The fix applies redis_max_allocation_size to Redis inline command lines and scans for CRLF before allocating parser arena memory. Inline command lines exceeding this limit are rejected.