CVE-2013-4787

Home/CVE/Android 1.6 Donut through 4.2 Jelly Bean does not properly check cryptographic signatures for applications, which allows

CVE

Android 1.6 Donut through 4.2 Jelly Bean does not properly check cryptographic signatures for applications, which allows

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.

HIGH · CVSS 9.3 EPSS 0.52603

Act now

EPSS ≥ 0.50 - high probability of exploitation in the next 30 days
EPSS percentile: top 2% of all CVEs by exploitation likelihood
Public exploit or PoC is available
CVSS base score ≥ 7.0

Sigma rules0 YARA rules0

Look this up elsewhere - one-click external pivots

NVD CVE.org CISA Vulners Exploit-DB GitHub PoC VulnCheck KEV GreyNoise

▸ How to read a CVE - triage first, then detect and patch

This page is every public fact about CVE-2013-4787, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.

Triage: should I act now? Four signals, and they are not interchangeable:

CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked. EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal. CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score. Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.

How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.

Then what - two workflows:

Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits. PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.

Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).

View attack path from CVE-2013-4787

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ATT&CK techniques

Techniques this CVE enables - linked via CWECAPECATT&CK. High◆ = named directly in ATT&CK or Nuclei templates.

T1190 · Exploit Public-Facing Application

▤ Build a SIEM detection for these techniques

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Weakness Classification

CWE-310Cryptographic Issues

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Affected Products & Versions

google androidall versions

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Public Exploits & PoCs

These PoC and exploit links come from public sources and are not verified to be safe or functional. Review the code before running anything, and treat unverified entries as untrusted.

remoteGoogle Android - 'APK' code Remote Security Bypassverified

pocARPSyndicate/cve-scores (trickest)

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