CVE-2021-3655 Information disclosure in kernel

Low 3.3 Published 5 Aug 2021 Updated 8 Oct 2026

Missing size validations in Linux kernel SCTP packets allow attackers to read uninitialized memory, potentially exposing sensitive data.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2021-3655?

CVE-2021-3655 is a low-severity vulnerability in Debian Debian Linux, published on 5 Aug 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A vulnerability was found in the Linux kernel in versions prior to v5.14-rc1. Missing size validations on inbound SCTP packets may allow the kernel to read uninitialized memory.

Weakness: CWE-20, CWE-909

Which versions are affected by CVE-2021-3655?

It affects 3 products.

Products include Debian Debian Linux, Linux kernel, Redhat Enterprise Linux.

How do I fix CVE-2021-3655?

Apply the vendor's patch.

Is CVE-2021-3655 being exploited?

There is no known exploitation of CVE-2021-3655 in the wild and no public exploit code.

All Debian Debian Linux vulnerabilities

Sources

Also known as A-197154735, ASB-A-197154735, AZL-6576, DEBIAN-CVE-2021-3655, GHSA-2r5v-rg6v-8xg5, UBUNTU-CVE-2021-3655.