Denial of service in Undertow

1) Memory leak

EUVDB-ID: #VU56025

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-3690

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform DoS attack on the target system.

The vulnerability exists due memory leak when processing incoming PONG messages. A remote attacker can force the application to leak memory by sending an websocket PONG message and perform denial of service attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Undertow: 2.0.0.Alpha1 - 2.2.9

CPE2.3

• cpe:2.3:a:red_hat:undertow:2.0.0.Alpha1:*:*:*:*:wildfly_core:*:*
• cpe:2.3:a:red_hat:undertow:2.0.0.Alpha2:*:*:*:*:wildfly_core:*:*
• cpe:2.3:a:red_hat:undertow:2.0.0:*:*:*:*:wildfly_core:*:*

External links

https://issues.redhat.com/browse/UNDERTOW-1935
https://bugzilla.redhat.com/show_bug.cgi?id=1991299

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.