CVE-2016-9909 Improper Neutralization of Input During Web Page Generation in html5lib
Remote attackers can execute arbitrary scripts via XSS due to mishandling of the less-than character in attribute values within the html5lib serializer.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2016-9909?
CVE-2016-9909 is a medium-severity cross-site scripting vulnerability in n/a, published on 22 Feb 2017. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
The serializer in html5lib before 0.99999999 might allow remote attackers to conduct cross-site scripting (XSS) attacks by leveraging mishandling of the < (less than) character in attribute values.
Weakness: CWE-79
Which versions are affected by CVE-2016-9909?
3 open source packages ship an affected version, including html5lib. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
html5lib PyPI | All versions | 0.999999999 |
html5lib PyPI | All versions | 0.999999999 |
html5lib PyPI | All versions | 0.999999999 |
Products include Html5lib Html5lib.
How do I fix CVE-2016-9909?
Upgrade html5lib to 0.999999999 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2016-9909 being exploited?
There is no known exploitation of CVE-2016-9909 in the wild and no public exploit code.
Other vulnerabilities in n/a
Sources
Also known as DEBIAN-CVE-2016-9909, GHSA-v9v9-xffq-rwr4, PYSEC-2017-14, UBUNTU-CVE-2016-9909.