Linux: Use After Free
CVE-2023-53282 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 51ab4eb1a25e73c7fc2ad9026520c4d8369c93cc, 8dfefa8f424ab208e552df1bfd008b732f3d0ad1, 8becb97918f04bb177bc9c4e00c2bdb302e00944 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 0.16% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 51ab4eb1a25e73c7fc2ad9026520c4d8369c93cc or 8dfefa8f424ab208e552df1bfd008b732f3d0ad1 or 8becb97918f04bb177bc9c4e00c2bdb302e00944 or 21681b81b9ae548c5dae7ae00d931197a27f480c, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.99 or 6.1.16 or 6.2.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 52d5244096017bbd11164479116baceaede342b0 up to, but not including, 51ab4eb1a25e73c7fc2ad9026520c4d8369c93cc; 52d5244096017bbd11164479116baceaede342b0 up to, but not including, 8dfefa8f424ab208e552df1bfd008b732f3d0ad1; 52d5244096017bbd11164479116baceaede342b0 up to, but not including, 8becb97918f04bb177bc9c4e00c2bdb302e00944; 52d5244096017bbd11164479116baceaede342b0 up to, but not including, 21681b81b9ae548c5dae7ae00d931197a27f480c; 3.0 | 51ab4eb1a25e73c7fc2ad9026520c4d8369c93cc, 8dfefa8f424ab208e552df1bfd008b732f3d0ad1, 8becb97918f04bb177bc9c4e00c2bdb302e00944, 21681b81b9ae548c5dae7ae00d931197a27f480c |
| Linux | Linux Kernel | before 5.15.99; 5.16 up to, but not including, 6.1.16; 6.2 up to, but not including, 6.2.3 | 5.15.99, 6.1.16, 6.2.3 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: scsi: lpfc: Fix use-after-free KFENCE violation during sysfs firmware write During the sysfs firmware write process, a use-after-free read warning is logged from the lpfc_wr_object() routine: BUG: KFENCE: use-after-free read in lpfc_wr_object+0x235/0x310 [lpfc] Use-after-free read at 0x0000000000cf164d (in kfence-#111): lpfc_wr_object+0x235/0x310 [lpfc] lpfc_write_firmware.cold+0x206/0x30d [lpfc] lpfc_sli4_request_firmware_update+0xa6/0x100 [lpfc] lpfc_request_firmware_upgrade_store+0x66/0xb0 [lpfc] kernfs_fop_write_iter+0x121/0x1b0 new_sync_write+0x11c/0x1b0 vfs_write+0x1ef/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x59/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd The driver accessed wr_object pointer data, which was initialized into mailbox payload memory, after the mailbox object was released back to the mailbox pool. Fix by moving the mailbox free calls to the end of the routine ensuring that we don't reference internal mailbox memory after release.
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: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.0 High severity
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