CVE-2023-39326
Published: December 6, 2023Last modified: July 22, 2025
Description
A malicious HTTP sender can use chunk extensions to cause a receiver reading from a request or response body to read many more bytes from the network than are in the body. A malicious HTTP client can further exploit this to cause a server to automatically read a large amount of data (up to about 1GiB) when a handler fails to read the entire body of a request. Chunk extensions are a little-used HTTP feature which permit including additional metadata in a request or response body sent using the chunked encoding. The net/http chunked encoding reader discards this metadata. A sender can exploit this by inserting a large metadata segment with each byte transferred. The chunk reader now produces an error if the ratio of real body to encoded bytes grows too small.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.3 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | LOW |
| Integrity impact | NONE |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | go | Fixed (1.21.7-r0) |
| Stream | go | Fixed (1.21.5-r0) | |
| Hardened Containers | 23 LTS | go | Fixed (1.21.7-r0) |
| Stream | go | Fixed (1.21.5-r0) |
References
- https://go.dev/cl/547335
- https://go.dev/issue/64433
- https://groups.google.com/g/golang-dev/c/6ypN5EjibjM/m/KmLVYH_uAgAJ
- https://lists.fedoraproject.org/archives/list/[email protected]/message/UIU6HOGV6RRIKWM57LOXQA75BGZSIH6G/
- https://pkg.go.dev/vuln/GO-2023-2382