TimescaleDB through 2.29.1, fixed in commit 517c13e, contains an out-of-bounds read in the Dictionary compression reverse row iterator (tsl/src/compression/algorithms/dictionary.c). The forward path …

Summary

TimescaleDB through 2.29.1, fixed in commit 517c13e, contains an out-of-bounds read in the Dictionary compression reverse row iterator (tsl/src/compression/algorithms/dictionary.c). The forward path validates the decoded index; the reverse path uses an assertion compiled out of release builds, leaving the 64-bit Simple8b index unvalidated and the read offset attacker-controlled. Attackers with DML access to a physical compressed relation can store a crafted datum and run a reverse-order scan. W…