Zero-day vulnerability in Oracle Java SE

Improper Input Validation
CVE-2012-1723

The vulnerability was exploited by BlackHole Exploit Toolkit after official patch.
The vulnerability was made public by Michael тАШmihiтАЩ Schierl.
According to Brian Krebs, the exploit was used in targeted attacks before official patch from Oracle.

Known malware:

Trojan.Maljava.

Vulnerability details

Advisory: SB2012061203 - Remote code execution in Oracle Java SE

Vulnerable component: Oracle Java SE

CVE-ID: CVE-2012-1723

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-20 - Improper input validation

Description:

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The weakness exists due to an error in the HotSpot bytecode verifier. By using untrusted Java Web Start applications and untrusted Java applets in a client deployment, a remote attacker can execute arbitrary code with privileges of the current user.

Successful exploitation of the vulnerability results in arbitrary code execution on the vulnerable system.

Note: the vulnerability was being actively exploited.

Public Exploits:

- Java Applet - Field Bytecode Verifier Cache Remote Code Execution (Metasploit) [Exploit-DB]

External links:

http://www.oracle.com/technetwork/topics/security/javacpujun2012-1515912.html
http://mail.openjdk.java.net/pipermail/distro-pkg-dev/2012-June/019076.html
https://www.symantec.com/connect/blogs/examination-java-vulnerability-cve-2012-1723
http://www.welivesecurity.com/2012/07/10/java-the-hutt-meets-cve-2012-1723-the-evil-empire-strikes-b...
https://threatpost.com/volume-malware-targeting-java-cve-2012-1723-flaw-spikes-080312/76878/
http://blog.crysys.hu/2012/07/on-the-cve-2012-1723-based-java-exploit-and-malware-sample/
http://krebsonsecurity.com/2012/07/new-java-exploit-to-debut-in-blackhole-exploit-kits/
https://wraithhacker.com/last-years-java-exploit-cve-2012-1723/

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.