The brace-expansion library generates arbitrary strings containing a common prefix and suffix. From 5.0.0 to before 5.0.6, the max option was being applied too late. When expanding a single large numeric range like {1..10000000}, the sequence generation loop generates all 10 million intermediate elements before the max limit is applied With max=10, the output is correctly limited to 10 items, but the process still allocates ~505 MB and spends ~800ms building the full intermediate array. This vulnerability is fixed in 5.0.6.
Weakness
The product does not properly control the allocation and maintenance of a limited resource.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Brace-expansion | Juliangruber | 5.0.0 (including) | 5.0.6 (excluding) |
| Red Hat Hardened Images | RedHat | nodejs26-main-26.3.0-1.2.hum1 | * |
| Red Hat Hardened Images | RedHat | rust-main-1.96.0-1.hum1 | * |
| Red Hat Hardened Images | RedHat | llvm21-main-21.1.8-6.hum1 | * |
| Red Hat Hardened Images | RedHat | nodejs25-main-25.9.0-1.1.hum1 | * |
| Red Hat Hardened Images | RedHat | llvm-main-21.1.8-1.1.hum1 | * |
| Red Hat Hardened Images | RedHat | yarnpkg-main-1.22.22-18.1.hum1 | * |
| Red Hat Hardened Images | RedHat | nodejs20-main-20.20.2-1.hum1 | * |
Potential Mitigations
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/147.html
- https://cwe.mitre.org/data/definitions/227.html
- https://cwe.mitre.org/data/definitions/492.html