YouTube Android Player API SDK: Use of Externally-Controlled Input to Select Classes or Code
CVE-2023-0460 is a high-severity use of externally-controlled input to select classes or code vulnerability in YouTube Android Player API SDK 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 YouTube Android Player API SDK versions: 1.2 through 1.2.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.11% 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
- Check which version of YouTube Android Player API SDK you run against the affected versions below, and install the vendor's latest release.
- 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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| YouTube Android Player API SDK | 1.2 through 1.2.2 | Not stated | |
| Youtube Android Player API | 1.2 through 1.2.2 | 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
- 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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.1 | Medium | CNA (google.com) |
| CVSS 3.1 | 7.3 | High | NVD |
Official description
The YouTube Embedded 1.2 SDK binds to a service within the YouTube Main App. After binding, a remote context is created with the flags Context.CONTEXT_INCLUDE_CODE | Context.CONTEXT_IGNORE_SECURITY. This allows the client app to remotely load code from YouTube Main App by retrieving the Main App’s ClassLoader. A potential vulnerability in the binding logic used by the client SDK where the SDK ends up calling bindService() on a malicious app rather than YT Main App. This creates a vulnerability where the SDK can load the malicious app’s ClassLoader instead, allowing the malicious app to load arbitrary code into the calling app whenever the embedded SDK is invoked. In order to trigger this vulnerability, an attacker must masquerade the Youtube app and install it on a device, have a second app that uses the Embedded player and typically distribute both to the victim outside of the Play Store.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Externally-Controlled Input to Select Classes or Code
The product uses external input with reflection to select which classes or code to use, but it does not sufficiently prevent the input from selecting improper classes or code.
How developers prevent this class of flaw
- Refactor your code to avoid using reflection.
- Do not use user-controlled inputs to select and load classes or code.
- Apply strict input validation by using allowlists or indirect selection to ensure that the user is only selecting allowable classes or code.
More Use of Externally-Controlled Input to Select Classes or Code vulnerabilities (CWE-470)
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
Other references
Recent Use of Externally-Controlled Input to Select Classes or Code vulnerabilities
- 9.8 Critical severity
- 7.8 High severity
- 8.0 High severity
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