Impact
rfc3161-client 1.0.2 and earlier contain a flaw in their timestamp response signature verification logic. In particular, it performs chain verification against the TSR's embedded certificates up to the trusted root(s), but fails to verify the TSR's own signature against the timestamping leaf certificates. Consequently, vulnerable versions perform insufficient signature validation to properly consider a TSR verified, as the attacker can introduce any TSR signature so long as the embedded leaf chains up to some root TSA.
Patches
Users should immediately upgrade to rfc3161-client 1.0.3 or later.
Workarounds
There is no workaround possible. Users should immediately upgrade to a fixed version.
Impact
rfc3161-client1.0.2 and earlier contain a flaw in their timestamp response signature verification logic. In particular, it performs chain verification against the TSR's embedded certificates up to the trusted root(s), but fails to verify the TSR's own signature against the timestamping leaf certificates. Consequently, vulnerable versions perform insufficient signature validation to properly consider a TSR verified, as the attacker can introduce any TSR signature so long as the embedded leaf chains up to some root TSA.Patches
Users should immediately upgrade to
rfc3161-client1.0.3 or later.Workarounds
There is no workaround possible. Users should immediately upgrade to a fixed version.