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MEDIUM5.3

GHSA-4v7x-pqxf-cx7m

net/http, x/net/http2: close connections when receiving too many headers

Quick fix

GHSA-4v7x-pqxf-cx7m — net/http: upgrade to the fixed version with the command below.

go get net/http@v1.21.9

Details

An attacker may cause an HTTP/2 endpoint to read arbitrary amounts of header data by sending an excessive number of CONTINUATION frames. Maintaining HPACK state requires parsing and processing all HEADERS and CONTINUATION frames on a connection. When a request's headers exceed MaxHeaderBytes, no memory is allocated to store the excess headers, but they are still parsed. This permits an attacker to cause an HTTP/2 endpoint to read arbitrary amounts of header data, all associated with a request which is going to be rejected. These headers can include Huffman-encoded data which is significantly more expensive for the receiver to decode than for an attacker to send. The fix sets a limit on the amount of excess header frames we will process before closing a connection.

Are you affected?

Enter the version of the package you're using.

Affected packages

Go/net/http
Introduced in: 0Fixed in: 1.21.9
Fixgo get net/http@v1.21.9
Go/golang.org/x/net/http2
Introduced in: 0Fixed in: 0.23.0
Fixgo get golang.org/x/net/http2@v0.23.0
Go/net/http
Introduced in: 1.22.0-0Fixed in: 1.22.2
Fixgo get net/http@v1.22.2
Go/golang.org/x/net
Introduced in: 0Fixed in: 0.23.0
Fixgo get golang.org/x/net@v0.23.0

References