CVE-2021-32824 Regular expression Denial of Service in MooTools

What is CVE-2021-32824?

CVE-2021-32824 is a critical unsafe deserialization vulnerability in Apache Dubbo, published on 3 Jan 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Apache Dubbo is a java based, open source RPC framework. Versions prior to 2.6.10 and 2.7.10 are vulnerable to pre-auth remote code execution via arbitrary bean manipulation in the Telnet handler. The Dubbo main service port can be used to access a Telnet Handler which offers some basic methods to collect information about the providers and methods exposed by the service and it can even allow to shutdown the service. This endpoint is unprotected. Additionally, a provider method can be invoked using the `invoke` handler. This handler uses a safe version of FastJson to process the call arguments. However, the resulting list is later processed with `PojoUtils.realize` which can be used to instantiate arbitrary classes and invoke its setters. Even though FastJson is properly protected with a default blocklist, `PojoUtils.realize` is not, and an attacker can leverage that to achieve remote code execution. Versions 2.6.10 and 2.7.10 contain fixes for this issue.

Weakness: CWE-502

Which versions are affected by CVE-2021-32824?

4 open source packages ship an affected version, including org.apache.dubbo:dubbo-parent. It affects 1 product.

Products include Apache Dubbo.

How do I fix CVE-2021-32824?

Upgrade org.apache.dubbo:dubbo-parent to a fixed version for your release line: 2.6.10 or 2.7.10.

Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.

Is CVE-2021-32824 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-32824 exists.

Other vulnerabilities in Apache Dubbo

• CVE-2023-29234 Bypass serialize checks in Apache Dubbo Critical 9.8
• CVE-2023-46279 Apache Dubbo: Bypass deny serialize list check in Apache Dubbo Critical 9.8
• CVE-2022-39198 Apache Dubbo Hession Deserialization Vulnerability Gadgets Bypass Critical 9.8
• CVE-2021-43297 Dubbo Hessian cause RCE when parse error Critical 9.8
• CVE-2021-36161 Unprotected input value toString cause RCE Critical 9.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-fprr-rrm8-4534.