CVE-2021-23351 Affecting golang-github-pires-go-proxyproto package, versions *


Severity

Recommended
0.0
medium
0
10

Based on Ubuntu security rating.

Threat Intelligence

EPSS
1.35% (80th percentile)

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  • Snyk IDSNYK-UBUNTU2204-GOLANGGITHUBPIRESGOPROXYPROTO-2785056
  • published25 Jun 2025
  • disclosed8 Mar 2021

Introduced: 8 Mar 2021

CVE-2021-23351  (opens in a new tab)

How to fix?

There is no fixed version for Ubuntu:22.04 golang-github-pires-go-proxyproto.

NVD Description

Note: Versions mentioned in the description apply only to the upstream golang-github-pires-go-proxyproto package and not the golang-github-pires-go-proxyproto package as distributed by Ubuntu. See How to fix? for Ubuntu:22.04 relevant fixed versions and status.

The package github.com/pires/go-proxyproto before 0.5.0 are vulnerable to Denial of Service (DoS) via the parseVersion1() function. The reader in this package is a default bufio.Reader wrapping a net.Conn. It will read from the connection until it finds a newline. Since no limits are implemented in the code, a deliberately malformed V1 header could be used to exhaust memory in a server process using this code - and create a DoS. This can be exploited by sending a stream starting with PROXY and continuing to send data (which does not contain a newline) until the target stops acknowledging. The risk here is small, because only trusted sources should be allowed to send proxy protocol headers.

CVSS Base Scores

version 3.1