1) Infinite loop

EUVDB-ID: #VU56634

Risk: Medium

CVSSv3.1: 5.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-41079

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

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to infinite loop when processing certain TLS packets. A remote attacker can send a specially crafted packet to the application, consume all available system resources and cause denial of service conditions.

Successful exploitation of vulnerability requires that Apache Tomcat is configured to use NIO+OpenSSL or NIO2+OpenSSL for TLS.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Apache Tomcat: 8.5.0, 8.5.1, 8.5.2, 8.5.3, 8.5.4, 8.5.5, 8.5.6, 8.5.7, 8.5.8, 8.5.9, 8.5.10, 8.5.11, 8.5.12, 8.5.13, 8.5.14, 8.5.15, 8.5.16, 8.5.17, 8.5.18, 8.5.19, 8.5.20, 8.5.21, 8.5.22, 8.5.23, 8.5.24, 8.5.25, 8.5.26, 8.5.27, 8.5.28, 8.5.29, 8.5.30, 8.5.31, 8.5.32, 8.5.33, 8.5.34, 8.5.35, 8.5.36, 8.5.37, 8.5.38, 8.5.39, 8.5.40, 8.5.41, 8.5.42, 8.5.43, 8.5.44, 8.5.45, 8.5.46, 8.5.47, 8.5.48, 8.5.49, 8.5.50, 8.5.51, 8.5.52, 8.5.53, 8.5.54, 8.5.55, 8.5.56, 8.5.57, 8.5.58, 8.5.59, 8.5.60, 8.5.61, 8.5.62, 8.5.63, 9.0.0, 9.0.0-M1, 9.0.0-M2, 9.0.0-M3, 9.0.0-M4, 9.0.0-M5, 9.0.0-M6, 9.0.0-M7, 9.0.0-M8, 9.0.0-M9, 9.0.0-M10, 9.0.0-M11, 9.0.0-M12, 9.0.0-M13, 9.0.0-M14, 9.0.0-M15, 9.0.0-M16, 9.0.0-M17, 9.0.0-M18, 9.0.0-M19, 9.0.0-M20, 9.0.0-M21, 9.0.0-M22, 9.0.0-M23, 9.0.0-M24, 9.0.0-M25, 9.0.0-M26, 9.0.0-M27, 9.0.1, 9.0.2, 9.0.3, 9.0.4, 9.0.5, 9.0.6, 9.0.7, 9.0.8, 9.0.9, 9.0.10, 9.0.11, 9.0.12, 9.0.13, 9.0.14, 9.0.15, 9.0.16, 9.0.17, 9.0.18, 9.0.19, 9.0.20, 9.0.21, 9.0.22, 9.0.23, 9.0.24, 9.0.25, 9.0.26, 9.0.27, 9.0.28, 9.0.29, 9.0.30, 9.0.31, 9.0.32, 9.0.33, 9.0.34, 9.0.35, 9.0.36, 9.0.37, 9.0.38, 9.0.39, 9.0.40, 9.0.41, 9.0.42, 9.0.43, 10.0.0, 10.0.0-M1, 10.0.0-M2, 10.0.0-M3, 10.0.0-M4, 10.0.0-M5, 10.0.0-M6, 10.0.0-M7, 10.0.0-M8, 10.0.0-M9, 10.0.0-M10, 10.0.0.0-M1, 10.0.1, 10.0.2

CPE2.3

• cpe:2.3:a:apache_foundation:apache_tomcat:10.0.2:*:*:*:*:*:*:*
• Full software list in CPE2.3 format available after registration.

External links

http://lists.apache.org/thread.html/rccdef0349fdf4fb73a4e4403095446d7fe6264e0a58e2df5c6799434%40%3Cannounce.tomcat.apache.org%3E

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.