Linux: Use After Free
CVE-2022-49015 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 8393ce5040803666bfa26a3a7bf41e44fab0ace9, 4b351609af4fdbc23f79ab2b12748f4403ea9af4, b35d899854d5d5d58eb7d7e7c0f61afc60d3a9e9 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 0.35% 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 8393ce5040803666bfa26a3a7bf41e44fab0ace9 or 4b351609af4fdbc23f79ab2b12748f4403ea9af4 or b35d899854d5d5d58eb7d7e7c0f61afc60d3a9e9 or 53a62c5efe91665f7a41fad0f888a96f94dc59eb, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.9.335 or 4.14.301 or 4.19.268 or 5.4.226, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | f421436a591d34fa5279b54a96ac07d70250cc8d up to, but not including, 8393ce5040803666bfa26a3a7bf41e44fab0ace9; f421436a591d34fa5279b54a96ac07d70250cc8d up to, but not including, 4b351609af4fdbc23f79ab2b12748f4403ea9af4; f421436a591d34fa5279b54a96ac07d70250cc8d up to, but not including, b35d899854d5d5d58eb7d7e7c0f61afc60d3a9e9; f421436a591d34fa5279b54a96ac07d70250cc8d up to, but not including, 53a62c5efe91665f7a41fad0f888a96f94dc59eb; f421436a591d34fa5279b54a96ac07d70250cc8d up to, but not including, 7ca81a161e406834a1fdc405fc83a572bd14b8d9; f421436a591d34fa5279b54a96ac07d70250cc8d up to, but not including, dca370e575d9b6c983f5015e8dc035e23e219ee6; f421436a591d34fa5279b54a96ac07d70250cc8d up to, but not including, f3add2b8cf620966de3ebfa07679ca12d33ec26f; f421436a591d34fa5279b54a96ac07d70250cc8d up to, but not including, 7e177d32442b7ed08a9fa61b61724abc548cb248; and 1 more ranges | 8393ce5040803666bfa26a3a7bf41e44fab0ace9, 4b351609af4fdbc23f79ab2b12748f4403ea9af4, b35d899854d5d5d58eb7d7e7c0f61afc60d3a9e9, 53a62c5efe91665f7a41fad0f888a96f94dc59eb, 7ca81a161e406834a1fdc405fc83a572bd14b8d9, dca370e575d9b6c983f5015e8dc035e23e219ee6 |
| Linux | Linux Kernel | 3.13 up to, but not including, 4.9.335; 4.10 up to, but not including, 4.14.301; 4.15 up to, but not including, 4.19.268; 4.20 up to, but not including, 5.4.226; 5.5 up to, but not including, 5.10.158; 5.11 up to, but not including, 5.15.82; 5.16 up to, but not including, 6.0.12; 6.1 | 4.9.335, 4.14.301, 4.19.268, 5.4.226, 5.10.158, 5.15.82 |
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 | 8.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: net: hsr: Fix potential use-after-free The skb is delivered to netif_rx() which may free it, after calling this, dereferencing skb may trigger use-after-free.
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/4b351609af4fdbc23f79ab2b12748f4403ea9af4
- git.kernel.org/stable/c/53a62c5efe91665f7a41fad0f888a96f94dc59eb
- git.kernel.org/stable/c/7ca81a161e406834a1fdc405fc83a572bd14b8d9
- git.kernel.org/stable/c/7e177d32442b7ed08a9fa61b61724abc548cb248
- git.kernel.org/stable/c/8393ce5040803666bfa26a3a7bf41e44fab0ace9
- git.kernel.org/stable/c/b35d899854d5d5d58eb7d7e7c0f61afc60d3a9e9
- git.kernel.org/stable/c/dca370e575d9b6c983f5015e8dc035e23e219ee6
- git.kernel.org/stable/c/f3add2b8cf620966de3ebfa07679ca12d33ec26f
Recent Use After Free vulnerabilities
- 7.0 High severity
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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