AccountService: Use After Free
CVE-2023-3297 is a high-severity use after free vulnerability in AccountService from Canonical, 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. There is no confirmed exploitation so far. EPSS estimates a 0.33% 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 Accountsservice to 23.13.9-2ubuntu2 or 22.08.8-1ubuntu7.1 or 22.07.5-2ubuntu1.4 or 0.6.55-0ubuntu12\~20.04.6, whichever matches your release line, or a later version.
- Read the advisory on bugs.launchpad.net for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Canonical | AccountService | Not specified in the record | Not stated |
| Canonical | Accountsservice | before 23.13.9-2ubuntu2; before 22.08.8-1ubuntu7.1; before 22.07.5-2ubuntu1.4; before 0.6.55-0ubuntu12\~20.04.6 | 23.13.9-2ubuntu2, 22.08.8-1ubuntu7.1, 22.07.5-2ubuntu1.4, 0.6.55-0ubuntu12\~20.04.6 |
| Canonical | Ubuntu Linux | 20.04; 22.04; 22.10; 23.04 | 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 | 8.1 | High | CNA (ubuntu.com) |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In Ubuntu's accountsservice an unprivileged local attacker can trigger a use-after-free vulnerability in accountsservice by sending a D-Bus message to the accounts-daemon process.
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: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-3297Third Party Advisory
Technical write-ups (may include proof of concept)
- securitylab.github.com/advisories/GHSL-2023-139_accountsservice/Exploit, Third Party Advisory
Recent Use After Free vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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