Denial of service in Apache Tomcat

1) Infinite loop

EUVDB-ID: #VU13986

Risk: Medium

CVSSv3.1: 7.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-1336

CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists due to improper handing of overflow in the UTF-8 decoder with supplementary characters. A remote attacker can send trigger an infinite loop in the decoder and cause the service to crash.

Mitigation

The vulnerability is addressed in the versions 7.0.88, 8.0.52, 8.5.31, 9.0.8.

Vulnerable software versions

Apache Tomcat: 7.0.28 - 9.0.7

External links

http://tomcat.apache.org/security-7.html#Fixed_in_Apache_Tomcat_7.0.88
http://tomcat.apache.org/security-8.html#Fixed_in_Apache_Tomcat_8.0.52
http://tomcat.apache.org/security-8.html#Fixed_in_Apache_Tomcat_8.5.31
http://tomcat.apache.org/security-9.html#Fixed_in_Apache_Tomcat_9.0.8

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.