CVE-2016-0762 Observable Discrepancy in Apache Tomcat
Attackers can determine valid usernames via timing attacks in Apache Tomcat Realm implementations, potentially aiding further authentication bypass attempts.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2016-0762?
CVE-2016-0762 is a medium-severity vulnerability in Apache Tomcat, published on 10 Aug 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The Realm implementations in Apache Tomcat versions 9.0.0.M1 to 9.0.0.M9, 8.5.0 to 8.5.4, 8.0.0.RC1 to 8.0.36, 7.0.0 to 7.0.70 and 6.0.0 to 6.0.45 did not process the supplied password if the supplied user name did not exist. This made a timing attack possible to determine valid user names. Note that the default configuration includes the LockOutRealm which makes exploitation of this vulnerability harder.
Weakness: CWE-203
Which versions are affected by CVE-2016-0762?
10 open source packages ship an affected version, including org.apache.tomcat:tomcat. It affects 15 products.
| Package | Affected | Fixed in |
|---|---|---|
org.apache.tomcat:tomcat Maven | From 6.0.0 | 6.0.46 |
org.apache.tomcat:tomcat Maven | From 6.0.0 | 6.0.46 |
org.apache.tomcat:tomcat Maven | From 7.0.0 | 7.0.72 |
org.apache.tomcat:tomcat Maven | From 7.0.0 | 7.0.72 |
org.apache.tomcat:tomcat Maven | From 8.0.0.RC1 | 8.0.37 |
org.apache.tomcat:tomcat Maven | From 8.0.0.RC1 | 8.0.37 |
4 more packages
org.apache.tomcat:tomcat Maven | From 8.5.0 | 8.5.5 |
org.apache.tomcat:tomcat Maven | From 8.5.0 | 8.5.5 |
org.apache.tomcat:tomcat Maven | From 9.0.0M1 | 9.0.0.M10 |
org.apache.tomcat:tomcat Maven | From 9.0.0M1 | 9.0.0.M10 |
Products include Apache Tomcat, Canonical Ubuntu Linux, Debian Debian Linux, Netapp Oncommand Insight, Netapp Oncommand Shift, Netapp Snap Creator Framework and 9 more.
How do I fix CVE-2016-0762?
Upgrade org.apache.tomcat:tomcat to a fixed version for your release line: 6.0.46, 7.0.72, 8.0.37 or 8.5.5.
Is CVE-2016-0762 being exploited?
There is no known exploitation of CVE-2016-0762 in the wild and no public exploit code.
Other vulnerabilities in Apache Tomcat
Sources
Also known as GHSA-wxcp-f2c8-x6xv, UBUNTU-CVE-2016-0762.