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

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-06-08 · updated 2026-06-17
Weakness: CWE-74

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.

Affected products

Fedoraproject Fedora: 38
Go: before 1.19.10; from 1.20.0 before 1.20.5 — fixed in 1.19.10, 1.20.5

How to fix

Upgrade to a fixed version: Go 1.19.10, 1.20.5. Check the vendor advisory for mitigations.

References

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