Linux: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2023-52502 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions e863f5720a5680e50c4cecf12424d7cc31b3eb0a, 7adcf014bda16cdbf804af5c164d94d5d025db2d, 6ac22ecdaad2ecc662048f8c6b0ceb1ca0699ef9 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 0.25% 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 e863f5720a5680e50c4cecf12424d7cc31b3eb0a or 7adcf014bda16cdbf804af5c164d94d5d025db2d or 6ac22ecdaad2ecc662048f8c6b0ceb1ca0699ef9 or d888d3f70b0de32b4f51534175f039ddab15eef8, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.19.297 or 5.4.259 or 5.10.199 or 5.15.136, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 8f50020ed9b81ba909ce9573f9d05263cdebf502 up to, but not including, e863f5720a5680e50c4cecf12424d7cc31b3eb0a; 8f50020ed9b81ba909ce9573f9d05263cdebf502 up to, but not including, 7adcf014bda16cdbf804af5c164d94d5d025db2d; 8f50020ed9b81ba909ce9573f9d05263cdebf502 up to, but not including, 6ac22ecdaad2ecc662048f8c6b0ceb1ca0699ef9; 8f50020ed9b81ba909ce9573f9d05263cdebf502 up to, but not including, d888d3f70b0de32b4f51534175f039ddab15eef8; 8f50020ed9b81ba909ce9573f9d05263cdebf502 up to, but not including, e4f2611f07c87b3ddb57c4b9e8efcd1e330fc3dc; 8f50020ed9b81ba909ce9573f9d05263cdebf502 up to, but not including, d1af8a39cf839d93c8967fdd858f6bbdc3e4a15c; 8f50020ed9b81ba909ce9573f9d05263cdebf502 up to, but not including, 31c07dffafce914c1d1543c135382a11ff058d93; 3.6 | e863f5720a5680e50c4cecf12424d7cc31b3eb0a, 7adcf014bda16cdbf804af5c164d94d5d025db2d, 6ac22ecdaad2ecc662048f8c6b0ceb1ca0699ef9, d888d3f70b0de32b4f51534175f039ddab15eef8, e4f2611f07c87b3ddb57c4b9e8efcd1e330fc3dc, d1af8a39cf839d93c8967fdd858f6bbdc3e4a15c |
| Linux | Linux Kernel | 3.6 up to, but not including, 4.19.297; 4.20 up to, but not including, 5.4.259; 5.5 up to, but not including, 5.10.199; 5.11 up to, but not including, 5.15.136; 5.16 up to, but not including, 6.1.59; 6.2 up to, but not including, 6.5.8; 6.6 | 4.19.297, 5.4.259, 5.10.199, 5.15.136, 6.1.59, 6.5.8 |
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
- AdjacentThe attacker must be on the same local network segment.
- 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:A/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 | 8.8 | High | CNA |
| CVSS 3.1 | 6.3 | Medium | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: net: nfc: fix races in nfc_llcp_sock_get() and nfc_llcp_sock_get_sn() Sili Luo reported a race in nfc_llcp_sock_get(), leading to UAF. Getting a reference on the socket found in a lookup while holding a lock should happen before releasing the lock. nfc_llcp_sock_get_sn() has a similar problem. Finally nfc_llcp_recv_snl() needs to make sure the socket found by nfc_llcp_sock_from_sn() does not disappear.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Concurrent Execution using Shared Resource with Improper Synchronization
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
How developers prevent this class of flaw
- In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
- Use thread-safe capabilities such as the data access abstraction in Spring.
- Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).
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/31c07dffafce914c1d1543c135382a11ff058d93
- git.kernel.org/stable/c/6ac22ecdaad2ecc662048f8c6b0ceb1ca0699ef9
- git.kernel.org/stable/c/7adcf014bda16cdbf804af5c164d94d5d025db2d
- git.kernel.org/stable/c/d1af8a39cf839d93c8967fdd858f6bbdc3e4a15c
- git.kernel.org/stable/c/d888d3f70b0de32b4f51534175f039ddab15eef8
- git.kernel.org/stable/c/e4f2611f07c87b3ddb57c4b9e8efcd1e330fc3dc
- git.kernel.org/stable/c/e863f5720a5680e50c4cecf12424d7cc31b3eb0a
Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
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- 7.5 High severity
- 7.4 High severity
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