Linux Kernel Use-After-Free
CVE-2022-2586 is a high-severity use after free vulnerability in linux from The Linux Kernel Organization, 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 4.14.316, 4.19.256, 5.4.211 as the first without the flaw, so updating linux to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on June 26, 2024, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update linux to 4.14.316 or 4.19.256 or 5.4.211 or 5.10.137, whichever matches your release line, or a later version.
- Update linux_kernel to 6.0-rc1 or a later version.
- Update SIMATIC S7-1500 TM MFP - GNU/Linux subsystem to V1.1 or a later version.
- CISA's required action: Apply updates per vendor instructions or discontinue use of the product if updates are unavailable.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| The Linux Kernel Organization | linux | 3.16 up to, but not including, 4.14.316; 4.15 up to, but not including, 4.19.256; 4.20 up to, but not including, 5.4.211; 5.5 up to, but not including, 5.10.137; 5.11 up to, but not including, 5.15.61; 5.16 up to, but not including, 5.18.18; 5.19 up to, but not including, 5.19.2 | 4.14.316, 4.19.256, 5.4.211, 5.10.137, 5.15.61, 5.18.18 |
| Linux | linux_kernel | before 6.0-rc1 | 6.0-rc1 |
| Siemens | SIMATIC S7-1500 TM MFP - GNU/Linux subsystem | before V1.1 | V1.1 |
| Siemens | Simatic S7-1500 Tm Mfp Firmware | before 1.1 | 1.1 |
| Siemens | Sinec OS | before 2.4 | 2.4 |
| Canonical | Ubuntu Linux | 14.04; 16.04; 18.04; 20.04; 22.04 | Not stated |
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 | 5.3 | Medium | CNA (ubuntu.com) |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
It was discovered that a nft object or expression could reference a nft set on a different nft table, leading to a use-after-free once that table was deleted.
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: active, automatable: no, technical impact: total).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Third-party and government advisories
- cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-2586Third Party Advisory
- ubuntu.com/security/notices/USN-5557-1Third Party Advisory
- ubuntu.com/security/notices/USN-5560-1Third Party Advisory
- ubuntu.com/security/notices/USN-5560-2Third Party Advisory
- ubuntu.com/security/notices/USN-5562-1Third Party Advisory
- ubuntu.com/security/notices/USN-5564-1Third Party Advisory
- ubuntu.com/security/notices/USN-5565-1Third Party Advisory
- ubuntu.com/security/notices/USN-5566-1Third Party Advisory
- ubuntu.com/security/notices/USN-5567-1Third Party Advisory
- ubuntu.com/security/notices/USN-5582-1Third Party Advisory
- zerodayinitiative.com/advisories/ZDI-22-1118/Third Party Advisory, VDB Entry
- cert-portal.siemens.com/productcert/html/ssa-794697.htmlThird Party Advisory
- cert-portal.siemens.com/productcert/html/ssa-806742.htmlThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-2586US Government Resource
Technical write-ups (may include proof of concept)
- vicarius.io/vsociety/posts/use-after-free-vulnerability-linked-chain-between-nft-tables-cve-2022-2586Exploit, Third Party Advisory
Other references
- openwall.com/lists/oss-security/2022/08/09/5Mailing List
Other vulnerabilities in linux
- 7.8 High severity
- 7.8 High severity
Recent Use After Free vulnerabilities
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- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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