CVE-2021-3690

A flaw was found in Undertow. A buffer leak on the incoming WebSocket PONG message may lead to memory exhaustion. This flaw allows an attacker to cause a denial of service. The highest threat from this vulnerability is availability.

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://access.redhat.com/security/cve/CVE-2021-3690
• https://bugzilla.redhat.com/show_bug.cgi?id=1991299
• https://github.com/undertow-io/undertow/commit/c7e84a0b7efced38506d7d1dfea5902366973877
• https://issues.redhat.com/browse/UNDERTOW-1935
• https://access.redhat.com/security/cve/CVE-2021-3690
• https://bugzilla.redhat.com/show_bug.cgi?id=1991299
• https://github.com/undertow-io/undertow/commit/c7e84a0b7efced38506d7d1dfea5902366973877
• https://issues.redhat.com/browse/UNDERTOW-1935