Privileged system crash via zero-length CIFS buffer
Published Aug 26, 2022 · Updated Aug 2, 2024
NULL pointer dereference in Linux Kernel 5.4 through 5.12 and 5.13-rc+HEAD allows local users with CAP_SYS_ADMIN to crash the system. smb2_ioctl_query_info accepts a zero output_buffer_length copied from userspace, after which memdup_user returns an invalid pointer that passes the error check and reaches an eight-byte copy. Exploitation requires a CIFS file and CAP_SYS_ADMIN; triggering the ioctl terminates the host rather than exposing or modifying data.
Summary
What happened
NULL pointer dereference in Linux Kernel 5.4 through 5.12 and 5.13-rc+HEAD allows local users with CAP_SYS_ADMIN to crash the system. smb2_ioctl_query_info accepts a zero output_buffer_length copied from userspace, after which memdup_user returns an invalid pointer that passes the error check and reaches an eight-byte copy. Exploitation requires a CIFS file and CAP_SYS_ADMIN; triggering the ioctl terminates the host rather than exposing or modifying data.
The record
- CVE
- CVE-2022-0168
- Published
- Aug 26, 2022
- Updated
- Aug 2, 2024
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-476, T1499.004
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Aug 26, 2022CVE publishedPublication date reported by the CVE source.
- Aug 2, 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=Affects v5.4–5.12, v5.13-rc+HEAD
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
- STAR Labs smb2_ioctl_query_info proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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