CyberSecBulletin
CVE-2024-43093Exploited in the wildNVD status: Analyzed

Android Framework Privilege Escalation

Published Updated By the CyberSecBulletin desk

CVE-2024-43093 is a high-severity improper handling of unicode encoding vulnerability in Android from Google, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. Affected Android versions: 15; 14; 13, and others listed below. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on November 7, 2024, which means attacks have been observed in the wild.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Check which version of Android you run against the affected versions below, and install the vendor's latest release.
  2. CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
  3. Read the advisory on source.android.com for workarounds and exact fixed builds.
  4. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
GoogleAndroid15; 14; 13; 12L; 12Not 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
RequiredA user must take an action such as opening a file or link.
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:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.3HighNVD
CVSS 3.17.3HighCISA (ADP)

Official description

In shouldHideDocument of ExternalStorageProvider.java, there is a possible bypass of a file path filter designed to prevent access to sensitive directories due to incorrect unicode normalization. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is needed for exploitation.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Handling of Unicode Encoding

The product does not properly handle when an input contains Unicode encoding.

How developers prevent this class of flaw

  • Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
  • Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

More Improper Handling of Unicode Encoding vulnerabilities (CWE-176)

Timeline

  1. Added to CISA's Known Exploited Vulnerabilities catalogue.
  2. CVE record published.
  3. CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
  4. Deadline for US federal agencies to remediate, set by CISA.
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in Android

All Android vulnerabilities

Recent Improper Handling of Unicode Encoding vulnerabilities

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