Kernel memory disclosure via mismatched register widths
Published May 10, 2021 · Updated Aug 4, 2024
Information disclosure in Linux Kernel 5.1-rc4 through 5.10-rc4 allows local users to read kernel stack memory via /proc//syscall. collect_syscall() casts the u64 argument array to unsigned long, so syscall_get_arguments() fills only 24 of the 48 printed bytes on 32-bit systems. Access requires CONFIG_HAVE_ARCH_TRACEHOOK and the applicable ptrace permission; exposed kernel addresses can defeat KASLR.
Summary
What happened
Information disclosure in Linux Kernel 5.1-rc4 through 5.10-rc4 allows local users to read kernel stack memory via /proc//syscall. collect_syscall() casts the u64 argument array to unsigned long, so syscall_get_arguments() fills only 24 of the 48 printed bytes on 32-bit systems. Access requires CONFIG_HAVE_ARCH_TRACEHOOK and the applicable ptrace permission; exposed kernel addresses can defeat KASLR.
The record
- CVE
- CVE-2020-28588
- Published
- May 10, 2021
- Updated
- Aug 4, 2024
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-681
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 10, 2021CVE 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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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=Linux Kernel v5.10-rc4,Linux Kernel v5.4.66,Linux Kernel v5.9.8
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- Cisco Talos /proc syscall disclosure demonstrationproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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