CVE-2024-54143: openwrt/asu allows build artifact poisoning via truncated SHA-256 hash and command injection

Severity: critical (CVSS 9.3 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-12-06 · updated 2026-06-17
Weakness: CWE-328

Description

openwrt/asu is an image on demand server for OpenWrt based distributions. The request hashing mechanism truncates SHA-256 hashes to only 12 characters. This significantly reduces entropy, making it feasible for an attacker to generate collisions. By exploiting this, a previously built malicious image can be served in place of a legitimate one, allowing the attacker to "poison" the artifact cache and deliver compromised images to unsuspecting users. This can be combined with other attacks, such as a command injection in Imagebuilder that allows malicious users to inject arbitrary commands into the build process, resulting in the production of malicious firmware images signed with the legitimate build key. This has been patched with 920c8a1.

Affected products

openwrt asu: before 920c8a1 — fixed in 920c8a1

How to fix

Upgrade to a fixed version: openwrt asu 920c8a1. Check the vendor advisory for mitigations.

References

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