What’s Vulnerable › Vulnerabilities

CVE-2021-23409: Denial of Service (DoS)

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-07-21 · updated 2026-06-17

Description

The package github.com/pires/go-proxyproto before 0.6.0 are vulnerable to Denial of Service (DoS) via creating connections without the proxy protocol header.

Affected products

• github.com/pires/go-proxyproto: before 0.6.0 — fixed in 0.6.0

How to fix

Upgrade to a fixed version: github.com/pires/go-proxyproto 0.6.0. Check the vendor advisory for mitigations.

References

• https://github.com/pires/go-proxyproto/issues/65
• https://github.com/pires/go-proxyproto/pull/74
• https://github.com/pires/go-proxyproto/pull/74/commits/cdc63867da24fc609b727231f682670d0d1cd346
• https://github.com/pires/go-proxyproto/releases/tag/v0.6.0
• https://snyk.io/vuln/SNYK-GOLANG-GITHUBCOMPIRESGOPROXYPROTO-1316439
• https://github.com/pires/go-proxyproto/issues/65
• https://github.com/pires/go-proxyproto/pull/74
• https://github.com/pires/go-proxyproto/pull/74/commits/cdc63867da24fc609b727231f682670d0d1cd346
• https://github.com/pires/go-proxyproto/releases/tag/v0.6.0
• https://snyk.io/vuln/SNYK-GOLANG-GITHUBCOMPIRESGOPROXYPROTO-1316439

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