# CVE-2013-4787: Security feature bypass in n/a

> Attackers can execute arbitrary code by installing a malicious APK that bypasses Android's cryptographic signature verification via Zip file manipulation.

- **Severity:** Critical 9.3 (`AV:N/AC:M/Au:N/C:C/I:C/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 9 Jul 2013
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-jvm8-c647-56v7

## What is CVE-2013-4787?

CVE-2013-4787 is a critical vulnerability in Google Android, published on 9 Jul 2013. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Android 1.6 Donut through 4.2 Jelly Bean does not properly check cryptographic signatures for applications, which allows attackers to execute arbitrary code via an application package file (APK) that is modified in a way that does not violate the cryptographic signature, probably involving multiple entries in a Zip file with the same name in which one entry is validated but the other entry is installed, aka Android security bug 8219321 and the "Master Key" vulnerability.

Weakness: CWE-310

## Which versions are affected by CVE-2013-4787?

It affects 1 product.


Products: Google Android.

## How do I fix CVE-2013-4787?

No fix has been published for CVE-2013-4787 yet. Limit exposure of the affected software until one is available.

## Is CVE-2013-4787 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2013-4787 exists.

Public exploit code:

- Google Android - 'APK' code Remote Security Bypass (exploitdb)

## Other vulnerabilities in Google Android

- [CVE-2026-58704](https://insights.sbomify.com/CVE-2026-58704/): Google Pixel Improper Authorization (high 8.8, exploited in the wild)
- [CVE-2025-48543](https://insights.sbomify.com/CVE-2025-48543/): Android Runtime Use-After-Free (high 8.8, exploited in the wild)
- [CVE-2023-35674](https://insights.sbomify.com/CVE-2023-35674/): Android Framework Privilege Escalation (high 8.8, exploited in the wild)
- [CVE-2025-48595](https://insights.sbomify.com/CVE-2025-48595/): Android Framework Integer Overflow (high 8.4, exploited in the wild)
- [CVE-2024-32896](https://insights.sbomify.com/CVE-2024-32896/): Android Pixel Privilege Escalation (high 8.1, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2013-4787 and fix it if it is affected.

What it is: CVE-2013-4787 is a critical vulnerability in Google Android, published on 9 Jul 2013. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2013-4787 exists.

Affected product: Google Android. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2013-4787/ (Markdown: https://insights.sbomify.com/CVE-2013-4787/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2013-4787
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2013-4787
- OSV: https://osv.dev/vulnerability/CVE-2013-4787

---
From sbomify Insights: https://insights.sbomify.com/CVE-2013-4787/
Summaries are generated and may contain mistakes; the official description above is the record.