SB2025092343 - F5 BIG-IP update for urllib
Published: September 23, 2025
Security Bulletin ID
SB2025092343
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) CRLF injection (CVE-ID: CVE-2019-9740)
The vulnerability allows a remote attacker to perform CRLF injection attacks.
The vulnerability exists within urllib2 implementation for Python 2.x and urllib3 implementation for Python 3.x when processing the path component of a URL after the "?" character within the urllib.request.urlopen() call. A remote attacker with ability to control URL, passed to the application, can use CRLF sequences to split the HTTP request and inject arbitrary HTTP headers into request, made by the application.
Remediation
Install update from vendor's website.