Kernel-memory disclosure via oversized virtual-console resize
Published Feb 6, 2020 · Updated Aug 4, 2024
Use-after-free in the Linux kernel through 5.5.2 allows local users to read kernel memory through virtual-console resize operations. When an oversized resize updates vc_size_row, vgacon_set_origin points vc_origin and vc_visible_origin at smaller VGA VRAM, and TIOCLINUX selection makes vgacon_invert_region calculate an out-of-range read. The trigger requires access to a VGA virtual console device, and the resulting invalid read exposes kernel data on the console.
Summary
What happened
Use-after-free in the Linux kernel through 5.5.2 allows local users to read kernel memory through virtual-console resize operations. When an oversized resize updates vc_size_row, vgacon_set_origin points vc_origin and vc_visible_origin at smaller VGA VRAM, and TIOCLINUX selection makes vgacon_invert_region calculate an out-of-range read. The trigger requires access to a VGA virtual console device, and the resulting invalid read exposes kernel data on the console.
The record
- CVE
- CVE-2020-8649
- Published
- Feb 6, 2020
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-416
- Attack vector
- physical
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 6, 2020CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- vgacon virtual-console resize reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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