CVE-2021-47587
A critical bug in the Linux kernel’s SYSTEMPORT driver can corrupt packet checksums when multiple transmit queues are used. The flaw allows the hardware to work on corrupted descriptors, leading to incorrect UDP/TCP checksums. The issue has been fixed by adding global locking for descriptor lifecycle.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Linux kernel, particularly version 5.16 and later, used on systems that employ the SYSTEMPORT network driver. Typical users include Linux server administrators and embedded device operators.
Real-world impact
An attacker could cause the kernel to send packets with wrong checksums, potentially disrupting network traffic or enabling packet manipulation. This could lead to denial of service or data integrity problems.
Why this severity
The CVSS score of 9.8 reflects that the vulnerability is exploitable from the network, requires no user interaction, and can compromise confidentiality, integrity, and availability of all data passing through the affected system.
What to do about it
- 01Upgrade the Linux kernel to version 5.16 or later.
NVD description
Timeline
- Jun 19, 2024 · Jun 19, 2024PublishedDisclosed and added to the National Vulnerability Database.
- Aug 4, 2026 · 2d agoAdvisory updatedThe NVD record was last revised.
- Aug 5, 2026 · 1d agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.
How it’s attacked
References & advisories
- git.kernel.org/stable/c/595a684fa6f23b2195…patch
- git.kernel.org/stable/c/6e1011cd183faae8da…patch
- git.kernel.org/stable/c/8b8e6e782456f1ce02…patch
- git.kernel.org/stable/c/8ed2f5d08d6e59f8c7…patch
- git.kernel.org/stable/c/c675256a7f131f5ba3…patch
- git.kernel.org/stable/c/de57f62f76450b934d…patch
- git.kernel.org/stable/c/eb4687c7442942e115…patch
- git.kernel.org/stable/c/f3fde37d3f0d429f0f…patch