CVE-2020-27589 – The Synopsys hub-rest-api-python library (PyPI ... (How to Fix)

📋 TL;DR

The Synopsys hub-rest-api-python library (PyPI package 'blackduck') versions 0.0.25 through 0.0.52 fail to properly validate SSL certificates in certain scenarios, allowing man-in-the-middle attacks. This vulnerability affects any application using these vulnerable versions to communicate with Synopsys Black Duck Hub servers. Attackers could intercept, modify, or inject data in API communications.

💻 Affected Systems

Products:

Synopsys hub-rest-api-python (PyPI package: blackduck)

Versions: 0.0.25 through 0.0.52

Operating Systems: All platforms using Python

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects applications that use the library's HTTPS functionality to communicate with Black Duck Hub servers.

📦 What is this software?

Hub Rest Api Python by Synopsys

View all CVEs affecting Hub Rest Api Python →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Full compromise of Black Duck Hub communications including credential theft, data manipulation, injection of malicious code, and complete loss of data integrity/confidentiality.

🟠

Likely Case

Man-in-the-middle attackers intercepting API traffic to steal authentication tokens, modify scan results, or inject false vulnerability data.

🟢

If Mitigated

Limited impact if communications occur only within trusted internal networks with proper network segmentation and monitoring.

🌐 Internet-Facing: HIGH - Any internet-facing API calls using vulnerable versions are susceptible to interception and manipulation.

🏢 Internal Only: MEDIUM - Internal attackers or compromised internal systems could still exploit this for lateral movement or data manipulation.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires network position to intercept traffic; no authentication bypass needed as this is a transport layer vulnerability.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 0.0.53 and later

Vendor Advisory: https://community.synopsys.com/s/question/0D52H00005JCZAXSA5/announcement-black-duck-defect-identified

Restart Required: No

Instructions:

1. Update the blackduck package: pip install --upgrade blackduck>=0.0.53
2. Verify the update: pip show blackduck
3. Restart any applications using the library
4. Test API connectivity to ensure proper certificate validation

🔧 Temporary Workarounds

Force certificate validation via environment

all

Set environment variables to enforce certificate validation in Python

export REQUESTS_CA_BUNDLE=/path/to/certfile
export CURL_CA_BUNDLE=/path/to/certfile

Implement certificate pinning

all

Add custom certificate validation logic in application code

# Python code to implement certificate pinning
import requests
from requests.adapters import HTTPAdapter
from requests.packages.urllib3.poolmanager import PoolManager
import ssl

class SSLAdapter(HTTPAdapter):
    def init_poolmanager(self, *args, **kwargs):
        ctx = ssl.create_default_context()
        ctx.check_hostname = True
        ctx.verify_mode = ssl.CERT_REQUIRED
        kwargs['ssl_context'] = ctx
        return super().init_poolmanager(*args, **kwargs)

session = requests.Session()
session.mount('https://', SSLAdapter())

🧯 If You Can't Patch

Restrict network access to Black Duck Hub servers to trusted internal networks only
Implement network monitoring and SSL/TLS inspection to detect man-in-the-middle attempts

🔍 How to Verify

Check if Vulnerable:

Check installed version: pip show blackduck | grep Version. If version is between 0.0.25 and 0.0.52 inclusive, system is vulnerable.

Check Version:

pip show blackduck | grep Version

Verify Fix Applied:

1. Verify version >=0.0.53: pip show blackduck | grep Version
2. Test API call with invalid certificate to ensure connection fails
3. Monitor logs for successful SSL handshakes

📡 Detection & Monitoring

Log Indicators:

Failed SSL certificate validation warnings
Unexpected API call failures after patch
Successful connections to servers with invalid certificates

Network Indicators:

Unencrypted or improperly encrypted traffic to Black Duck Hub servers
SSL/TLS handshake failures after remediation

SIEM Query:

source="*python*" AND ("SSL" OR "certificate") AND ("warning" OR "error" OR "failed") AND "blackduck"

📊 Metadata

CVE ID: CVE-2020-27589

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CWE: CWE-295

Published: November 6, 2020

Last Updated: November 21, 2024

🔗 References

https://community.synopsys.com/s/question/0D52H00005JCZAXSA5/announcement-black-duck-defect-identified Vendor Advisory
https://github.com/blackducksoftware/hub-rest-api-python Third Party Advisory
https://github.com/blackducksoftware/hub-rest-api-python/pull/113/commits/273b27d0de1004389dd8cf43c40b1197c787e7cd Patch,Third Party Advisory
https://pypi.org/project/blackduck/ Third Party Advisory
https://www.optiv.com/explore-optiv-insights/source-zero/certificate-validation-disabled-black-duck-api-wrapper Exploit,Third Party Advisory
https://community.synopsys.com/s/question/0D52H00005JCZAXSA5/announcement-black-duck-defect-identified Vendor Advisory
https://github.com/blackducksoftware/hub-rest-api-python Third Party Advisory
https://github.com/blackducksoftware/hub-rest-api-python/pull/113/commits/273b27d0de1004389dd8cf43c40b1197c787e7cd Patch,Third Party Advisory
https://pypi.org/project/blackduck/ Third Party Advisory
https://www.optiv.com/explore-optiv-insights/source-zero/certificate-validation-disabled-black-duck-api-wrapper Exploit,Third Party Advisory

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