Android Framework Privilege Escalation
CVE-2023-20963 is a high-severity improper certificate validation vulnerability in Android, 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. Affected Android versions: Android-11 Android-12 Android-12L Android-13. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on April 13, 2023, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of Android you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: Apply updates per vendor instructions.
- Read the advisory on source.android.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Android | Android | Android-11 Android-12 Android-12L Android-13 | 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 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In WorkSource, there is a possible parcel mismatch. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11 Android-12 Android-12L Android-13Android ID: A-220302519
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How developers prevent this class of flaw
- Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
More Improper Certificate Validation vulnerabilities (CWE-295)
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-20963Third Party Advisory, US Government Resource
Other vulnerabilities in Android
- 5.5 Medium severity
Android Pixel Information Disclosure Exploited
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Improper Certificate Validation vulnerabilities
- 9.8 Critical severity
- 7.5 High severity
- 8.1 High severity
- 7.4 High severity
- 7.4 High severity
- 9.1 Critical severity
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