Linux: Use After Free
CVE-2023-53219 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 dd5c77814f290b353917df329f36de1472d47154, 90229e9ee957d4514425e4a4d82c50ab5d57ac4d, 1550bcf2983ae1220cc8ab899a39a423fa7cb523 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 dd5c77814f290b353917df329f36de1472d47154 or 90229e9ee957d4514425e4a4d82c50ab5d57ac4d or 1550bcf2983ae1220cc8ab899a39a423fa7cb523 or f9982db735a8495eee14267cf193c806b957e942, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.14.316 or 4.19.284 or 5.4.244 or 5.10.181, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e up to, but not including, dd5c77814f290b353917df329f36de1472d47154; 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e up to, but not including, 90229e9ee957d4514425e4a4d82c50ab5d57ac4d; 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e up to, but not including, 1550bcf2983ae1220cc8ab899a39a423fa7cb523; 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e up to, but not including, f9982db735a8495eee14267cf193c806b957e942; 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e up to, but not including, 051af3f0b7d1cd8ab7f3e2523ad8ae1af44caba3; 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e up to, but not including, 07821524f67bf920342bc84ae8b3dea2a315a89e; 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e up to, but not including, c8f9c05e1ebcc9c7bc211cc8b74d8fb86a8756fc; 52b1eaf4c59a3bbd07afbb4ab4f43418a807d02e up to, but not including, 0f5bb36bf9b39a2a96e730bf4455095b50713f63; and 1 more ranges | dd5c77814f290b353917df329f36de1472d47154, 90229e9ee957d4514425e4a4d82c50ab5d57ac4d, 1550bcf2983ae1220cc8ab899a39a423fa7cb523, f9982db735a8495eee14267cf193c806b957e942, 051af3f0b7d1cd8ab7f3e2523ad8ae1af44caba3, 07821524f67bf920342bc84ae8b3dea2a315a89e |
| Linux | Linux Kernel | 4.3 up to, but not including, 4.14.316; 4.15 up to, but not including, 4.19.284; 4.20 up to, but not including, 5.4.244; 5.5 up to, but not including, 5.10.181; 5.11 up to, but not including, 5.15.113; 5.16 up to, but not including, 6.1.30; 6.2 up to, but not including, 6.3.4; 6.4 | 4.14.316, 4.19.284, 5.4.244, 5.10.181, 5.15.113, 6.1.30 |
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: media: netup_unidvb: fix use-after-free at del_timer() When Universal DVB card is detaching, netup_unidvb_dma_fini() uses del_timer() to stop dma->timeout timer. But when timer handler netup_unidvb_dma_timeout() is running, del_timer() could not stop it. As a result, the use-after-free bug could happen. The process is shown below: (cleanup routine) | (timer routine) | mod_timer(&dev->tx_sim_timer, ..) netup_unidvb_finidev() | (wait a time) netup_unidvb_dma_fini() | netup_unidvb_dma_timeout() del_timer(&dma->timeout); | | ndev->pci_dev->dev //USE Fix by changing del_timer() to del_timer_sync().
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
- git.kernel.org/stable/c/051af3f0b7d1cd8ab7f3e2523ad8ae1af44caba3
- git.kernel.org/stable/c/07821524f67bf920342bc84ae8b3dea2a315a89e
- git.kernel.org/stable/c/0f5bb36bf9b39a2a96e730bf4455095b50713f63
- git.kernel.org/stable/c/1550bcf2983ae1220cc8ab899a39a423fa7cb523
- git.kernel.org/stable/c/90229e9ee957d4514425e4a4d82c50ab5d57ac4d
- git.kernel.org/stable/c/c8f9c05e1ebcc9c7bc211cc8b74d8fb86a8756fc
- git.kernel.org/stable/c/dd5c77814f290b353917df329f36de1472d47154
- git.kernel.org/stable/c/f9982db735a8495eee14267cf193c806b957e942
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
- 7.8 High severity
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