Local privilege escalation via invalid kernel-buffer free
Published Sep 19, 2021 · Updated Aug 4, 2024
Invalid buffer release in Linux kernel 5.10 through 5.14.6 allows local users to gain privileges through io_uring buffer selection. loop_rw_iter increments req->rw.addr after each segment even when IORING_OP_PROVIDE_BUFFERS makes it reference a kernel io_buffer, so io_put_kbuf frees an adjacent buffer at an attacker-controlled offset. Unprivileged local access is sufficient to execute arbitrary kernel-context code and obtain elevated privileges.
Summary
What happened
Invalid buffer release in Linux kernel 5.10 through 5.14.6 allows local users to gain privileges through io_uring buffer selection. loop_rw_iter increments req->rw.addr after each segment even when IORING_OP_PROVIDE_BUFFERS makes it reference a kernel io_buffer, so io_put_kbuf frees an adjacent buffer at an attacker-controlled offset. Unprivileged local access is sufficient to execute arbitrary kernel-context code and obtain elevated privileges.
The record
- CVE
- CVE-2021-41073
- Published
- Sep 19, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-763, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 19, 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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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
- Linux_LPE_io_uring_CVE-2021-41073proof of concept · demonstrated
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Technologies
Your stack
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Your stack
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