CVE-2016-10539

negotiator is an HTTP content negotiator for Node.js and is used by many modules and frameworks including Express and Koa. The header for Accept-Language, when parsed by negotiator 0.6.0 and earlier is vulnerable to Regular Expression Denial of Service via a specially crafted string.

Weakness

The product does not properly control the allocation and maintenance of a limited resource.

Affected Software

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

References

• https://nodesecurity.io/advisories/106
• https://nodesecurity.io/advisories/106