What’s Vulnerable › Vulnerabilities

CVE-2020-28974

• Severity: medium (CVSS 5.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-11-20 · updated 2026-06-17
• Weakness: CWE-125

Description

A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height.

Affected products

• Debian Linux: 9.0
• Linux kernel: before 5.9.7 — fixed in 5.9.7

How to fix

Upgrade to a fixed version: Linux kernel 5.9.7. Check the vendor advisory for mitigations.

References

• http://www.openwall.com/lists/oss-security/2020/11/25/1
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9.7
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3c4e0dff2095c579b142d5a0693257f1c58b4804
• https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html
• https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html
• https://seclists.org/oss-sec/2020/q4/104
• https://security.netapp.com/advisory/ntap-20210108-0003/
• http://www.openwall.com/lists/oss-security/2020/11/25/1
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9.7
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3c4e0dff2095c579b142d5a0693257f1c58b4804
• https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html
• https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html

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