@grpc/grpc-js: In certain configurations, getAuthContext can return unauthorized certificates as though they were authorized

@grpc/grpc-js implements the core functionality of gRPC purely in JavaScript, without a C++ addon. Prior to 1.13.6 and 1.14.5, getAuthContext does not distinguish authorized from unauthorized peer certificates when server credentials set requireClientCertificate to false. When applications use the returned authentication context, they can treat an unauthorized certificate as authorized, causing improper authentication. @grpc/grpc-js-xds can reach this condition when RBAC authentication is enabled in affected configurations. This issue is fixed in version 1.14.5 and 1.13.6.

@grpc/grpc-js: The server transmits some error messages thrown by method handlers to the client in status messages

@grpc/grpc-js implements the core functionality of gRPC purely in JavaScript, without a C++ addon. Prior to 1.13.6 and 1.14.5, when an application method handler throws an uncaught error, the server includes its error message in the status message sent to the client. The thrown error message is transmitted to the client, causing sensitive information disclosure when the message contains sensitive data. This issue is fixed in versions 1.13.6 and 1.14.5.

@grpc/grpc-js: The exact path match matcher incorrectly only applies a prefix match for case-insensitive matches

@grpc/grpc-js implements the core functionality of gRPC purely in JavaScript, without a C++ addon. Prior to 1.13.1 and 1.14.1, the exact path (method name) matcher used by RBAC performs a prefix comparison instead of an equality comparison when case-insensitive matching is enabled. If one service method name prefixes another and the methods have different access rules, a request for the longer method can match the shorter method's rule and cause incorrect authorization. This issue is fixed in versions 1.13.1 and 1.14.1.

gRPC-Go: Denial of Service (DoS) via crash due to missing `:authority` and `Host` headers in the xDS servers

gRPC-Go is the Go language implementation of gRPC. Prior to 1.82.2 and 1.83.2, servers created with xds.NewGRPCServer() allow internal/transport/http2_server.go to accept an RPC containing neither the :authority header nor the Host header, while RouteAndProcess in internal/xds/server/routing.go assumes that an authority value exists and indexes the empty slice. A remote client that can complete transport connection establishment can trigger an index-out-of-bounds panic that is not recovered by the per-RPC goroutine and terminates the entire server process. In insecure or ordinary TLS deployments the request can be unauthenticated, while strict mTLS or ALTS deployments require valid transport credentials before the malformed RPC can reach the interceptor. This issue is fixed in versions 1.82.2 and 1.83.2.

gRPC-Go: xDS RBAC HTTP Filter bypass via mixed-case Header Matching and gRFC A41 validation evasion

gRPC-Go is the Go language implementation of gRPC. Prior to 1.83.1, the xDS RBAC HTTP filter in internal/xds/httpfilter/rbac/rbac.go does not lowercase header matcher names in normalizeHeaderMatcher even though incoming metadata keys are lowercase. A DENY policy using a mixed-case name such as X-Role or User-Agent therefore does not match and fails open, allowing requests that should be rejected. The same case mismatch permits :Scheme or Grpc-Status to evade gRFC A41 validation and prevents Host from being rewritten to :authority. This issue is fixed in version 1.83.1.

gRPC-Go has an authorization bypass via missing leading slash in :path

gRPC-Go is the Go language implementation of gRPC. Versions prior to 1.79.3 have an authorization bypass resulting from improper input validation of the HTTP/2 `:path` pseudo-header. The gRPC-Go server was too lenient in its routing logic, accepting requests where the `:path` omitted the mandatory leading slash (e.g., `Service/Method` instead of `/Service/Method`). While the server successfully routed these requests to the correct handler, authorization interceptors (including the official `grpc/authz` package) evaluated the raw, non-canonical path string. Consequently, "deny" rules defined using canonical paths (starting with `/`) failed to match the incoming request, allowing it to bypass the policy if a fallback "allow" rule was present. This affects gRPC-Go servers that use path-based authorization interceptors, such as the official RBAC implementation in `google.golang.org/grpc/authz` or custom interceptors relying on `info.FullMethod` or `grpc.Method(ctx)`; AND that have a security policy contains specific "deny" rules for canonical paths but allows other requests by default (a fallback "allow" rule). The vulnerability is exploitable by an attacker who can send raw HTTP/2 frames with malformed `:path` headers directly to the gRPC server. The fix in version 1.79.3 ensures that any request with a `:path` that does not start with a leading slash is immediately rejected with a `codes.Unimplemented` error, preventing it from reaching authorization interceptors or handlers with a non-canonical path string. While upgrading is the most secure and recommended path, users can mitigate the vulnerability using one of the following methods: Use a validating interceptor (recommended mitigation); infrastructure-level normalization; and/or policy hardening.

gRPC-Go: Heap Memory Exhaustion (OOM) via HTTP/2 DATA Frame Fragmentation

gRPC-Go is the Go language implementation of gRPC. Prior to 1.83.1, internal/transport/transport.go stores each fragmented HTTP/2 DATA frame as a separate recvMsg in recvBuffer, so millions of one-byte frames can consume disproportionate heap memory even when payload bytes remain within connection and stream flow-control windows. An unauthenticated remote attacker can use concurrent multiplexed streams to exhaust process memory and cause a runtime panic or out-of-memory termination. Receive-buffer compaction is enabled by default and can be controlled temporarily with GRPC_GO_EXPERIMENTAL_ENABLE_RECEIVE_BUFFER_COMPACTION. This issue is fixed in version 1.83.1.

HTTP/2: Multiple HTTP/2 enabled web servers are vulnerable to a DDoS attack (Rapid Reset Attack)

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

@grpc/grps-js: A malformed request can cause a server crash

@grpc/grps-js implements the core functionality of gRPC purely in JavaScript, without a C++ addon. Prior to 1.9.16, 1.10.12, 1.11.4, 1.12.7, 1.13.5, and 1.14.4, an invalid incoming HTTP/2 stream initiation can cause a server process created using @grpc/grpc-js to crash. This issue is fixed in versions 1.9.16, 1.10.12, 1.11.4, 1.12.7, 1.13.5, and 1.14.4.

@grpc/grps-js: An incoming malformed compressed message can cause a client or server crash

@grpc/grps-js implements the core functionality of gRPC purely in JavaScript, without a C++ addon. Prior to 1.9.16, 1.10.12, 1.11.4, 1.12.7, 1.13.5, and 1.14.4, an invalid incoming compressed message can cause a client or server process that uses @grpc/grpc-js to crash. This issue is fixed in versions 1.9.16, 1.10.12, 1.11.4, 1.12.7, 1.13.5, and 1.14.4.

Denial of Service in gRPC Core

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.

Denial of Service through Data corruption in gRPC-C++

There exists a denial of service through Data corruption in gRPC-C++ - gRPC-C++ servers with transmit zero copy enabled through the channel arg GRPC_ARG_TCP_TX_ZEROCOPY_ENABLED can experience data corruption issues. The data sent by the application may be corrupted before transmission over the network thus leading the receiver to receive an incorrect set of bytes causing RPC requests to fail. We recommend upgrading past commit e9046b2bbebc0cb7f5dc42008f807f6c7e98e791

HPACK table poisoning in gRPC C++, Python & Ruby

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.

Google gRPC before 2017-02-22 has an out-of-bounds write caused by a heap-based buffer overflow related to the parse_unix function in core/ext/client_channel/parse_address.c.

Google gRPC before 2017-02-22 has an out-of-bounds write related to the gpr_free function in core/lib/support/alloc.c.

Google gRPC before 2017-04-05 has an out-of-bounds write caused by a heap-based buffer overflow related to core/lib/iomgr/error.c.

Google gRPC before 2017-03-29 has an out-of-bounds write caused by a heap-based use-after-free related to the grpc_call_destroy function in core/lib/surface/call.c.

Denial-of-Service in gRPC

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

Denial-of-Service in gRPC

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…

Information leak in gRPC

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