Linux: Use After Free
CVE-2022-48697 is a critical-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 17f121ca3ec6be0fb32d77c7f65362934a38cc8e, 8d66989b5f7bb28bba2f8e1e2ffc8bfef4a10717, be01f1c988757b95f11f090a9f491365670a522b as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.59% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Linux to 17f121ca3ec6be0fb32d77c7f65362934a38cc8e or 8d66989b5f7bb28bba2f8e1e2ffc8bfef4a10717 or be01f1c988757b95f11f090a9f491365670a522b or ebf46da50beb78066674354ad650606a467e33fa, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.19.260 or 5.4.213 or 5.10.143 or 5.15.68, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | a07b4970f464f13640e28e16dad6cfa33647cc99 up to, but not including, 17f121ca3ec6be0fb32d77c7f65362934a38cc8e; a07b4970f464f13640e28e16dad6cfa33647cc99 up to, but not including, 8d66989b5f7bb28bba2f8e1e2ffc8bfef4a10717; a07b4970f464f13640e28e16dad6cfa33647cc99 up to, but not including, be01f1c988757b95f11f090a9f491365670a522b; a07b4970f464f13640e28e16dad6cfa33647cc99 up to, but not including, ebf46da50beb78066674354ad650606a467e33fa; a07b4970f464f13640e28e16dad6cfa33647cc99 up to, but not including, 4484ce97a78171668c402e0c45db7f760aea8060; a07b4970f464f13640e28e16dad6cfa33647cc99 up to, but not including, 6a02a61e81c231cc5c680c5dbf8665275147ac52; 4.8 | 17f121ca3ec6be0fb32d77c7f65362934a38cc8e, 8d66989b5f7bb28bba2f8e1e2ffc8bfef4a10717, be01f1c988757b95f11f090a9f491365670a522b, ebf46da50beb78066674354ad650606a467e33fa, 4484ce97a78171668c402e0c45db7f760aea8060, 6a02a61e81c231cc5c680c5dbf8665275147ac52 |
| Linux | Linux Kernel | 4.8 up to, but not including, 4.19.260; 4.20 up to, but not including, 5.4.213; 5.5 up to, but not including, 5.10.143; 5.11 up to, but not including, 5.15.68; 5.16 up to, but not including, 5.19.9; 6.0 | 4.19.260, 5.4.213, 5.10.143, 5.15.68, 5.19.9 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | CNA |
| CVSS 3.1 | 5.3 | Medium | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: nvmet: fix a use-after-free Fix the following use-after-free complaint triggered by blktests nvme/004: BUG: KASAN: user-memory-access in blk_mq_complete_request_remote+0xac/0x350 Read of size 4 at addr 0000607bd1835943 by task kworker/13:1/460 Workqueue: nvmet-wq nvme_loop_execute_work [nvme_loop] Call Trace: show_stack+0x52/0x58 dump_stack_lvl+0x49/0x5e print_report.cold+0x36/0x1e2 kasan_report+0xb9/0xf0 __asan_load4+0x6b/0x80 blk_mq_complete_request_remote+0xac/0x350 nvme_loop_queue_response+0x1df/0x275 [nvme_loop] __nvmet_req_complete+0x132/0x4f0 [nvmet] nvmet_req_complete+0x15/0x40 [nvmet] nvmet_execute_io_connect+0x18a/0x1f0 [nvmet] nvme_loop_execute_work+0x20/0x30 [nvme_loop] process_one_work+0x56e/0xa70 worker_thread+0x2d1/0x640 kthread+0x183/0x1c0 ret_from_fork+0x1f/0x30
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/17f121ca3ec6be0fb32d77c7f65362934a38cc8e
- git.kernel.org/stable/c/4484ce97a78171668c402e0c45db7f760aea8060
- git.kernel.org/stable/c/6a02a61e81c231cc5c680c5dbf8665275147ac52
- git.kernel.org/stable/c/8d66989b5f7bb28bba2f8e1e2ffc8bfef4a10717
- git.kernel.org/stable/c/be01f1c988757b95f11f090a9f491365670a522b
- git.kernel.org/stable/c/ebf46da50beb78066674354ad650606a467e33fa
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.4 High severity
- 9.8 Critical severity
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