Grpc

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.

Published: 2024-08-06T10:14:28.492Z
Updated: 2024-08-06T13:17:59.082Z

Lack of error handling in the TCP server in Google's gRPC starting version 1.23 on posix-compatible platforms (ex. Linux) allows an attacker to cause a denial of service by initiating a significant number of connections with the server. Note that gRPC C++ Python, and Ruby are affected, but gRPC Java, and Go are NOT affected.

Published: 2023-09-13T16:31:55.664Z
Updated: 2026-01-12T15:34:12.725Z

gRPC contains a vulnerability that allows hpack table accounting errors could lead to unwanted disconnects between clients and servers in exceptional cases/ Three vectors were found that allow the following DOS attacks: - Unbounded memory buffering in the HPACK parser - Unbounded CPU consumption in the HPACK parser The unbounded CPU consumption is down to a copy that occurred per-input-block in the parser, and because that could be unbounded due to the memory copy bug we end up with an O(n^2) parsing loop, with n selected by the client. The unbounded memory buffering bugs: - The header size limit check was behind the string reading code, so we needed to first buffer up to a 4 gigabyte string before rejecting it as longer than 8 or 16kb. - HPACK varints have an encoding quirk whereby an infinite number of 0’s can be added at the start of an integer. gRPC’s hpack parser needed to read all of them before concluding a parse. - gRPC’s metadata overflow check was performed per frame, so that the following sequence of frames could cause infinite buffering: HEADERS: containing a: 1 CONTINUATION: containing a: 2 CONTINUATION: containing a: 3 etc…

Published: 2023-08-09T12:54:47.415Z
Updated: 2024-09-27T18:40:52.297Z

gRPC contains a vulnerability whereby a client can cause a termination of connection between a HTTP2 proxy and a gRPC server: a base64 encoding error for `-bin` suffixed headers will result in a disconnection by the gRPC server, but is typically allowed by HTTP2 proxies. We recommend upgrading beyond the commit in  https://github.com/grpc/grpc/pull/32309 https://www.google.com/url

Published: 2023-06-09T10:48:15.075Z
Updated: 2025-02-13T16:55:01.392Z

When gRPC HTTP2 stack raised a header size exceeded error, it skipped parsing the rest of the HPACK frame. This caused any HPACK table mutations to also be skipped, resulting in a desynchronization of HPACK tables between sender and receiver. If leveraged, say, between a proxy and a backend, this could lead to requests from the proxy being interpreted as containing headers from different proxy clients - leading to an information leak that can be used for privilege escalation or data exfiltration. We recommend upgrading beyond the commit contained in  https://github.com/grpc/grpc/pull/33005 https://github.com/grpc/grpc/pull/33005

Published: 2023-06-09T10:54:08.472Z
Updated: 2024-09-26T19:12:06.245Z