Observable Timing Discrepancy in Tink-Java and Tink-Android ChunkedMacVerification
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.2epss 0.2%
exploitation probability
0.2%top 92% of all CVEs
observed exploitation
nono source reports it
When verifying a mac with a ChunkedMacVerification object, Tink compares the resulting tag with non constant time comparison. This potentially allows an attacker to use timinig information as a side channel in order to get information how many bytes of a given tag match the correct tag. This in turn could allow to find a correct tag bytewise.
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N