CVE-2013-4314: pyopenssl - Spoofing SSL Servers via Crafted Certificate
Summary
CVE-2013-4314: The X509Extension in pyOpenSSL before 0.13.1 does not properly handle a '\0' character in a domain name in the Subject Alternative Name field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arb... Affects pyopenssl versions < 0.13.1. Fixed in 0.13.1. How to fix ↓
Also tracked for
- pyopenssl · Debian:11
The same CVE-2013-4314 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
pyopenssl is a Python library that provides a high-level interface to the OpenSSL library, allowing developers to integrate SSL/TLS functionality into their Python applications. It is commonly used for secure communication over networks. However, prior to version 0.13.1, pyopenssl is vulnerable to a spoofing attack that allows an attacker to impersonate arbitrary SSL servers using a crafted certificate issued by a legitimate Certification Authority.
Vulnerability Detail
The vulnerability lies in the X509Extension component of pyopenssl. When processing the Subject Alternative Name field of an X.509 certificate, pyopenssl fails to properly handle a '\0' character in a domain name. This flaw can be exploited by a man-in-the-middle attacker to create a certificate with a malicious domain name that appears valid to the victim's browser or application. As a result, the attacker can intercept and manipulate secure communications, leading to potential data leakage or unauthorized access.
How To Fix
Minimum fixed version
0.13.1
This is the first release that contains the fix.
pip install --upgrade "pyopenssl==0.13.1"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
There is no known workaround for this vulnerability. It is recommended to update to the latest version of pyopenssl as soon as possible.
Conclusion
The vulnerability in pyopenssl prior to version 0.13.1 allows for SSL server spoofing through the use of a crafted certificate. To mitigate this risk, it is crucial to update to the latest version of pyopenssl. For further assistance or support in vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for pyopenssl →
FAQ
You can check the version of pyopenssl by running the following command:
pip show pyopenssl
No, this vulnerability affects all systems where pyopenssl version 0.13.0 or earlier is installed.
Yes, an attacker can exploit this vulnerability remotely by intercepting the victim's network traffic and presenting a crafted certificate.
There are no known instances of this vulnerability being actively exploited at this time.
You can find more information about this vulnerability in the official pyopenssl advisory: [link to advisory]
Related vulnerabilities
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