GO-2022-0289 BIT-golang-2021-44717 CVE-2021-44717

Misdirected I/O in syscall

Not rated yet Go

Severity: Not rated yet; No source has published a CVSS score yet
Exploit chance (EPSS): 2.00%; Chance of exploitation in the next 30 days. Higher than 80.73% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: —; Not classified
Fix: 1.17.5; Upgrade stdlib to this version or later

Description

When a Go program running on a Unix system is out of file descriptors and calls syscall.ForkExec (including indirectly by using the os/exec package), syscall.ForkExec can close file descriptor 0 as it fails. If this happens (or can be provoked) repeatedly, it can result in misdirected I/O such as writing network traffic intended for one connection to a different connection, or content intended for one file to a different one.

For users who cannot immediately update to the new release, the bug can be mitigated by raising the per-process file descriptor limit.

Affected versions

Go

Package	Vulnerable	Fixed in
stdlib	`< 1.16.12` `>= 1.17.0-0, < 1.17.5`	`1.16.12` `1.17.5`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

stdlib Go → `1.17.5`

go

go get stdlib@v1.17.5 && go mod tidy

References

Fixes and patches

Issue reports

go.dev/issue/50057

Timeline

May 18, 2022 Published
May 20, 2024 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-4374-p667-p6c8 HTTP/2 rapid reset can cause excessive work in net/http	High Known exploited	Also affects stdlib
CVE-2020-0601 Certificate validation bypass on Windows in crypto/x509	High Known exploited	Also affects stdlib
RUSTSEC-2026-0382 Distrust compromised intermediate certificates in crypto/x509	Medium	Also affects stdlib
GO-2026-6613 HTTP/1 server connection desynchronization after 2xx CONNECT response in net/http	High	Also affects stdlib
GO-2026-6609 Lack of limit on size of parsed Range headers in net/http	High	Also affects stdlib
GO-2026-6608 Memory limit bypass when parsing MIME headers in net/textproto, mime/multipart	High	Also affects stdlib
GO-2026-6607 Reject malformed ECH outer extension references in crypto/tls	High	Also affects stdlib
GO-2026-6604 Root.Mkdir(All) can follow junctions out of the root on Windows in os	Critical	Also affects stdlib

Credits: Kamil Trzciński of GitLab, Tomasz Maczukin

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