Linux: Use After Free
CVE-2022-49275 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 d93ed9aff64968f4cdad690712eb4f48ae537bde, d3892a747ab16b1eb6593a19d29f62c3b3f020ac, 7728d937ec403a1ceff9483023252d2cb8777f81 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 0.28% 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 d93ed9aff64968f4cdad690712eb4f48ae537bde or d3892a747ab16b1eb6593a19d29f62c3b3f020ac or 7728d937ec403a1ceff9483023252d2cb8777f81 or 08d90846e438ac22dc56fc49ec0b0d195831c5ed, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.9.324 or 4.14.289 or 4.19.253 or 5.4.207, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 80646733f11c2e9de3b6339f7e635047e6087280 up to, but not including, d93ed9aff64968f4cdad690712eb4f48ae537bde; 80646733f11c2e9de3b6339f7e635047e6087280 up to, but not including, d3892a747ab16b1eb6593a19d29f62c3b3f020ac; 80646733f11c2e9de3b6339f7e635047e6087280 up to, but not including, 7728d937ec403a1ceff9483023252d2cb8777f81; 80646733f11c2e9de3b6339f7e635047e6087280 up to, but not including, 08d90846e438ac22dc56fc49ec0b0d195831c5ed; 80646733f11c2e9de3b6339f7e635047e6087280 up to, but not including, 869016a2938ac44f7b2fb7fc22c89edad99eb9b3; 80646733f11c2e9de3b6339f7e635047e6087280 up to, but not including, f43e64076ff1b1dcb893fb77ad1204105f710a29; 80646733f11c2e9de3b6339f7e635047e6087280 up to, but not including, 4db7d6f481990dd179a9ee7126dc7aa31ea4fff3; 80646733f11c2e9de3b6339f7e635047e6087280 up to, but not including, 31417073493f302d26ab66b3abc098d43227b835; and 2 more ranges | d93ed9aff64968f4cdad690712eb4f48ae537bde, d3892a747ab16b1eb6593a19d29f62c3b3f020ac, 7728d937ec403a1ceff9483023252d2cb8777f81, 08d90846e438ac22dc56fc49ec0b0d195831c5ed, 869016a2938ac44f7b2fb7fc22c89edad99eb9b3, f43e64076ff1b1dcb893fb77ad1204105f710a29 |
| Linux | Linux Kernel | 3.18 up to, but not including, 4.9.324; 4.10 up to, but not including, 4.14.289; 4.15 up to, but not including, 4.19.253; 4.20 up to, but not including, 5.4.207; 5.5 up to, but not including, 5.10.110; 5.11 up to, but not including, 5.15.33; 5.16 up to, but not including, 5.16.19; 5.17 up to, but not including, 5.17.2 | 4.9.324, 4.14.289, 4.19.253, 5.4.207, 5.10.110, 5.15.33 |
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 CISA (ADP).
Official description
In the Linux kernel, the following vulnerability has been resolved: can: m_can: m_can_tx_handler(): fix use after free of skb can_put_echo_skb() will clone skb then free the skb. Move the can_put_echo_skb() for the m_can version 3.0.x directly before the start of the xmit in hardware, similar to the 3.1.x branch.
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/08d90846e438ac22dc56fc49ec0b0d195831c5ed
- git.kernel.org/stable/c/2e8e79c416aae1de224c0f1860f2e3350fa171f8
- git.kernel.org/stable/c/31417073493f302d26ab66b3abc098d43227b835
- git.kernel.org/stable/c/4db7d6f481990dd179a9ee7126dc7aa31ea4fff3
- git.kernel.org/stable/c/7728d937ec403a1ceff9483023252d2cb8777f81
- git.kernel.org/stable/c/869016a2938ac44f7b2fb7fc22c89edad99eb9b3
- git.kernel.org/stable/c/d3892a747ab16b1eb6593a19d29f62c3b3f020ac
- git.kernel.org/stable/c/d93ed9aff64968f4cdad690712eb4f48ae537bde
- git.kernel.org/stable/c/f43e64076ff1b1dcb893fb77ad1204105f710a29
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
Spotted an error? Tell us.