# What is CVE-2013-0422?

> CVE-2013-0422 is a critical-severity flaw (CVSS 9.8) in JDK from Oracle, published on 10 January 2013. It is on the list of flaws known to be exploited, so criminals are already using it. The latest forecast puts its chance of use in the next 30 days at 97%. If you run an affected version, patch it first.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2013-0422

## At a glance

- **Verdict:** Fix this now. Attackers are using this flaw today. If you run an affected version, it goes to the top of your list.
- **Precursor Intelligence risk score:** 89 out of 100 (Critical); action: Emergency patch. Kept up to date as the evidence changes.
- **Severity:** Critical (CVSS 9.8 out of 10)
- **Known to be exploited:** Yes, it is on the government list of flaws known to be exploited
- **Chance of use in the next 30 days:** 97% (latest exploit-likelihood forecast)
- **Published:** 10 January 2013
- **Record last updated:** 22 October 2025
- **Main product:** JDK from Oracle
- **Affected products:** 4

## What is CVE-2013-0422? In plain terms

It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.

### The official description

Multiple vulnerabilities in Oracle Java 7 before Update 11 allow remote attackers to execute arbitrary code by (1) using the public getMBeanInstantiator method in the JmxMBeanServer class to obtain a reference to a private MBeanInstantiator object, then retrieving arbitrary Class references using the findClass method, and (2) using the Reflection API with recursion in a way that bypasses a security check by the java.lang.invoke.MethodHandles.Lookup.checkSecurityManager method due to the inability of the sun.reflect.Reflection.getCallerClass method to skip frames related to the new reflection API, as exploited in the wild in January 2013, as demonstrated by Blackhole and Nuclear Pack, and a different vulnerability than CVE-2012-4681 and CVE-2012-3174. NOTE: some parties have mapped the recursive Reflection API issue to CVE-2012-3174, but CVE-2012-3174 is for a different vulnerability whose details are not public as of 20130114.  CVE-2013-0422 covers both the JMX/MBean and Reflection API issues.  NOTE: it was originally reported that Java 6 was also vulnerable, but the reporter has retracted this claim, stating that Java 6 is not exploitable because the relevant code is called in a way that does not bypass security checks.  NOTE: as of 20130114, a reliable third party has claimed that the findClass/MBeanInstantiator vector was not fixed in Oracle Java 7 Update 11.  If there is still a vulnerable condition, then a separate CVE identifier might be created for the unfixed issue.

### What kind of flaw is it?

- CWE-284: Improper Access Control

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Easy: no special conditions
- Login needed first: No login needed
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can read data, change data and take it offline

Severity vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Is CVE-2013-0422 being exploited? Yes

Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at 97%.

Exploit likelihood over the last 7 days: 97%, 97%, 97%, 97%, 97%, 97%, 97%.

### Timeline

- 10 January 2013: Published
- 22 October 2025: Record last updated

### How Precursor Intelligence ranks it

CVE-2013-0422 scores **89 out of 100 (Critical)**, with the action "Emergency patch".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2013-0422?

The published record lists 4 products.

- [JDK](https://www.precursorintelligence.com/product/oracle/jdk) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 1.7.0, 1.7.0-update1, 1.7.0-update2, 1.7.0-update3, 1.7.0-update4, 1.7.0-update5, 1.7.0-update6, 1.7.0-update7, 1.7.0-update9, 1.7.0-update10
- [JRE](https://www.precursorintelligence.com/product/oracle/jre) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Application): 1.7.0, 1.7.0-update1, 1.7.0-update2, 1.7.0-update3, 1.7.0-update4, 1.7.0-update5, 1.7.0-update6, 1.7.0-update7, 1.7.0-update9, 1.7.0-update10
- [Opensuse](https://www.precursorintelligence.com/product/opensuse/opensuse) by [Opensuse](https://www.precursorintelligence.com/vendors/opensuse) (Operating system): 12.2
- [Ubuntu Linux](https://www.precursorintelligence.com/product/canonical/ubuntu_linux) by [Canonical](https://www.precursorintelligence.com/vendors/canonical) (Operating system): 12.10

## How do I fix CVE-2013-0422?

1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisory first in the list.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Check it wasn’t used before you patched.** Because criminals are already using this flaw, look for signs of a break-in on affected systems using the vendor’s guidance.

### References

- [oracle.com](http://www.oracle.com/technetwork/topics/security/alert-cve-2013-0422-1896849.html) (Vendor advisory)
- [blog.fireeye.com](http://blog.fireeye.com/research/2013/01/happy-new-year-from-new-java-zero-day.html) (Not applicable)
- [blog.fuseyism.com](http://blog.fuseyism.com/index.php/2013/01/15/security-icedtea-2-1-4-2-2-4-2-3-4-released/) (Broken link)
- [immunityproducts.blogspot.ca](http://immunityproducts.blogspot.ca/2013/01/confirmed-java-only-fixed-one-of-two.html) (Third-party advisory)
- [krebsonsecurity.com](http://krebsonsecurity.com/2013/01/zero-day-java-exploit-debuts-in-crimeware/) (Third-party advisory)
- [labs.alienvault.com](http://labs.alienvault.com/labs/index.php/2013/new-year-new-java-zeroday/) (Broken link, Third-party advisory)
- [lists.opensuse.org](http://lists.opensuse.org/opensuse-security-announce/2013-01/msg00025.html) (Mailing list, Third-party advisory)
- [malware.dontneedcoffee.com](http://malware.dontneedcoffee.com/2013/01/0-day-17u10-spotted-in-while-disable.html) (Third-party advisory)
- [rhn.redhat.com](http://rhn.redhat.com/errata/RHSA-2013-0156.html) (Third-party advisory)
- [rhn.redhat.com](http://rhn.redhat.com/errata/RHSA-2013-0165.html) (Third-party advisory)
- [seclists.org](http://seclists.org/bugtraq/2013/Jan/48) (Mailing list, Third-party advisory)
- [kb.cert.org](http://www.kb.cert.org/vuls/id/625617) (Third-party advisory, Government resource)
- [mandriva.com](http://www.mandriva.com/security/advisories?name=MDVSA-2013:095) (Not applicable)
- [ubuntu.com](http://www.ubuntu.com/usn/USN-1693-1) (Third-party advisory)
- [us-cert.gov](http://www.us-cert.gov/cas/techalerts/TA13-010A.html) (Third-party advisory, Government resource)
- [partners.immunityinc.com](https://partners.immunityinc.com/idocs/Java%20MBeanInstantiator.findClass%200day%20Analysis.pdf) (Broken link)
- [threatpost.com](https://threatpost.com/en_us/blogs/nasty-new-java-zero-day-found-exploit-kits-already-have-it-011013) (Not applicable)
- [wiki.mageia.org](https://wiki.mageia.org/en/Support/Advisories/MGASA-2013-0018) (Third-party advisory)
- [www-304.ibm.com](https://www-304.ibm.com/connections/blogs/PSIRT/entry/oracle_java_7_security_manager_bypass_vulnerability_cve_2013_04224?lang=en_us) (Not applicable)
- [cisa.gov](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2013-0422)

## Questions

### What is CVE-2013-0422?

CVE-2013-0422 is a critical-severity flaw in JDK from Oracle, published on 10 January 2013. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.

### How serious is CVE-2013-0422?

It scores 9.8 out of 10 on the CVSS severity scale, which is critical. Our risk score for CVE-2013-0422 is 89 out of 100, which is Critical. Its action is "Emergency patch". Attackers are using this flaw today. If you run an affected version, it goes to the top of your list.

### Is CVE-2013-0422 being exploited?

Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at 97%.

### Which versions does CVE-2013-0422 affect?

For JDK from Oracle: 1.7.0, 1.7.0-update1, 1.7.0-update2, 1.7.0-update3, 1.7.0-update4, 1.7.0-update5 and 4 more. The record lists 4 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2013-0422?

Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet. Because criminals are already using it, also check affected systems for signs of a break-in.

## Does CVE-2013-0422 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
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