HPACK table poisoning in gRPC C++, Python & Ruby
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.3epss 0.2%
exploitation probability
0.2%top 87% of all CVEs
observed exploitation
nono source reports it
It's possible for a gRPC client communicating with a HTTP/2 proxy to poison the HPACK table between the proxy and the backend such that other clients see failed requests. It's also possible to use this vulnerability to leak other clients HTTP header keys, but not values.
This occurs because the error status for a misencoded header is not cleared between header reads, resulting in subsequent (incrementally indexed) added headers in the first request being poisoned until cleared from the HPACK table.
Please update to a fixed version of gRPC as soon as possible. This bug has been fixed in 1.58.3, 1.59.5, 1.60.2, 1.61.3, 1.62.3, 1.63.2, 1.64.3, 1.65.4.
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L
Affected products
Google · gRPC