#VU51012 Deserialization of Untrusted Data in Apache Tomcat - CVE-2021-25329

Vulnerability identifier: #VU51012

Vulnerability risk: Medium

CVSSv4.0: 6.9 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-25329

CWE-ID: CWE-502

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Apache Tomcat
Server applications / Web servers

Vendor: Apache Foundation

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data. A remote attacker can pass specially crafted data to the application and execute arbitrary code on the target system.

Note, the vulnerability exists due to incomplete fix for #VU28158 and requires a certain specific configuration.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Apache Tomcat: 7.0.0 - 7.0.107, 8.0.0 RC1 - 8.0.53, 8.5.0 - 8.5.62, 9.0.0-M1 - 9.0.42, 10.0.0-M1 - 10.0.1

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External links
https://lists.apache.org/thread.html/rfe62fbf9d4c314f166fe8c668e50e5d9dd882a99447f26f0367474bf%40%3Cannounce.tomcat.apache.org%3E

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Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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