Linux: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2022-49919 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in Linux, with a CVSS 3.1 base score of 7.0 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 74fd5839467054cd9c4d050614d3ee8788386171, b2d7a92aff0fbd93c29d2aa6451fb99f050e2c4e, 6044791b7be707fd0e709f26e961a446424e5051 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 74fd5839467054cd9c4d050614d3ee8788386171 or b2d7a92aff0fbd93c29d2aa6451fb99f050e2c4e or 6044791b7be707fd0e709f26e961a446424e5051 or 4ab6f96444e936f5e4a936d5c0bc948144bcded3, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.4.224 or 5.10.154 or 5.15.78 or 5.18, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 5b8d63489c3b701eb2a76f848ec94d8cbc9373b9 up to, but not including, 74fd5839467054cd9c4d050614d3ee8788386171; 330c0c6cd2150a2d7f47af16aa590078b0d2f736 up to, but not including, b2d7a92aff0fbd93c29d2aa6451fb99f050e2c4e; e33d9bd563e71f6c6528b96008d65524a459c4dc up to, but not including, 6044791b7be707fd0e709f26e961a446424e5051; 9dd732e0bdf538b1b76dc7c157e2b5e560ff30d3 up to, but not including, 4ab6f96444e936f5e4a936d5c0bc948144bcded3; 9dd732e0bdf538b1b76dc7c157e2b5e560ff30d3 up to, but not including, 26b5934ff4194e13196bedcba373cd4915071d0e; 80de9ea1f5b808a6601e91111fae601df2b26369; ab9f34a30c23f656e76f4c5b83125a4e7b53c86e; 5.4.198 up to, but not including, 5.4.224; and 5 more ranges | 74fd5839467054cd9c4d050614d3ee8788386171, b2d7a92aff0fbd93c29d2aa6451fb99f050e2c4e, 6044791b7be707fd0e709f26e961a446424e5051, 4ab6f96444e936f5e4a936d5c0bc948144bcded3, 26b5934ff4194e13196bedcba373cd4915071d0e, 5.4.224 |
| Linux | Linux Kernel | 5.4.198 up to, but not including, 5.4.224; 5.10.122 up to, but not including, 5.10.154; 5.15.47 up to, but not including, 5.15.78; 5.17.15 up to, but not including, 5.18; 5.18.4 up to, but not including, 6.0.8; 6.1 | 5.4.224, 5.10.154, 5.15.78, 5.18, 6.0.8 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- 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:H/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 | CNA |
| CVSS 3.1 | 7.0 | High | NVD |
| CVSS 3.1 | 7.0 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: release flow rule object from commit path No need to postpone this to the commit release path, since no packets are walking over this object, this is accessed from control plane only. This helped uncovered UAF triggered by races with the netlink notifier.
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: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/26b5934ff4194e13196bedcba373cd4915071d0e
- git.kernel.org/stable/c/4ab6f96444e936f5e4a936d5c0bc948144bcded3
- git.kernel.org/stable/c/6044791b7be707fd0e709f26e961a446424e5051
- git.kernel.org/stable/c/74fd5839467054cd9c4d050614d3ee8788386171
- git.kernel.org/stable/c/b2d7a92aff0fbd93c29d2aa6451fb99f050e2c4e
Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
- 8.1 High severity
- 7.5 High severity
- 7.0 High severity
- 7.0 High severity
- 7.0 High severity
- 7.8 High severity
Spotted an error? Tell us.