CVE-2012-0955

TLS certificate validation vulnerability in software-properties (before version 0.92)

• CVSS 7.4
• CWE-295: Improper Certificate Validation
• Cryptographic
• Remote

software-properties was vulnerable to a person-in-the-middle attack due to incorrect TLS certificate validation in softwareproperties/ppa.py. software-properties didn't check TLS certificates under python2 and only checked certificates under python3 if a valid certificate bundle was provided. Fixed in software-properties version 0.92.

CVE

CVE-2012-0955

CWE

CWE-295: Improper Certificate Validation

CVSS base score

7.4

Published

2020-12-02

OWASP

A05 Security Misconfiguration

Orthogonal defect classification

Checking

Code defect classification

Missing Check

Category

Cryptographic

Subcategory

Improper SSL/TLS Certificate Validation

Accessibility scope

Remote

Impact

Information Disclosure

Fixed by upgrading

Yes

Solution

Update to software-properties version 0.92 or higher

import urllib.request

def fetch_data(url):
    response = urllib.request.urlopen(url)
    return response.read()

url = "https://example.com/data"
data = fetch_data(url)
print(data)

import ssl
import urllib.request

def fetch_data(url):
    context = ssl.create_default_context()

    with urllib.request.urlopen(url, context=context) as response:
        return response.read()

url = "https://example.com/data"
data = fetch_data(url)
print(data)

@misc{vaitp:cve20120955,
  title        = {{TLS certificate validation vulnerability in software-properties (before version 0.92)}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2020},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2012-0955},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2012-0955/}}
}