# CVE-2016-5549: Oracle Java SE ECDSA timing attack in Libraries

Source: https://junglewise.ai/threats/cve-2016-5549-oracle-java-se-ecdsa-timing-attack-in-libraries  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2017-01-27. Updated: 2026-05-13  
License: CC BY 4.0 with a link back

CVE-2016-5549 · Severity: medium · CVSS 6.5 · Published 2017-01-27

A vulnerability in Oracle Java's core libraries could allow an attacker to gain unauthorized access to sensitive data. This issue primarily affects desktop users running Java applets or Web Start applications that process untrusted content from the internet. To be successful, an attacker must convince a user to interact with a malicious website or application.

Technologies: [Oracle Java SE](https://junglewise.ai/threats/technologies/java-se), [Oracle Java SE Embedded](https://junglewise.ai/threats/technologies/java-se-embedded). Vendors: [Oracle](https://junglewise.ai/threats/vendors/oracle).

## Quick answers

**Is CVE-2016-5549 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2016-5549 being exploited in the wild.

**How severe is CVE-2016-5549?** Medium severity, with a CVSS score of 6.5, published 27 January 2017.

**Which products and versions are affected?** Oracle Java SE 7u121, 8u112; Oracle Java SE Embedded 8u111.

**Is there a fix for CVE-2016-5549?** A patch was published on 2017-01-19: Red Hat released security updates addressing this vulnerability. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2016-5549 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2016-5549?** Check whether you run Oracle Java SE or Oracle Java SE Embedded at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

This vulnerability is a timing attack within the Elliptic Curve Digital Signature Algorithm (ECDSA) implementation in the Oracle Java SE Libraries subcomponent. An unauthenticated attacker can exploit this over a network via multiple protocols, though the attack requires human interaction (User Interaction: Required). The flaw specifically impacts Java deployments that rely on the sandbox for security, such as Java Web Start applications and applets. Successful exploitation can lead to unauthorized access to critical data or complete access to all data accessible by the Java environment. Oracle addressed this in the January 2017 Critical Patch Update.

## Affected products

- Oracle Java SE 7u121, 8u112
- Oracle Java SE Embedded 8u111

## Timeline

- 2017-01-19: patched: Red Hat released security updates addressing this vulnerability.
- 2017-01-27: disclosed: NVD published the vulnerability details.

## References

- [http://rhn.redhat.com/errata/RHSA-2017-0175.html](http://rhn.redhat.com/errata/RHSA-2017-0175.html)
- [http://rhn.redhat.com/errata/RHSA-2017-0176.html](http://rhn.redhat.com/errata/RHSA-2017-0176.html)
- [http://rhn.redhat.com/errata/RHSA-2017-0263.html](http://rhn.redhat.com/errata/RHSA-2017-0263.html)
- [http://rhn.redhat.com/errata/RHSA-2017-0336.html](http://rhn.redhat.com/errata/RHSA-2017-0336.html)
- [http://rhn.redhat.com/errata/RHSA-2017-0337.html](http://rhn.redhat.com/errata/RHSA-2017-0337.html)
- [http://rhn.redhat.com/errata/RHSA-2017-0338.html](http://rhn.redhat.com/errata/RHSA-2017-0338.html)
- [http://www.oracle.com/technetwork/security-advisory/cpujan2017-2881727.html](http://www.oracle.com/technetwork/security-advisory/cpujan2017-2881727.html)

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