Ethical Hacking News
Legacy Python Bootstrap Scripts Exposed: Unveiling the Domain-Takeover Risk
ReversingLabs discovered potentially exploitable code in legacy Python packages.A bootstrap script fetches and executes a script for the Distribute package from python-distribute.org, which was removed in 2013.The vulnerable code persists due to affected packages still shipping it.One example is the slapos.core package, included in Tornado, which poses a significant risk to users.A malicious package named "spellcheckers" was uploaded to PyPI on November 15, 2025, containing code for remote access trojan (RAT) execution.ReversingLabs emphasizes the importance of addressing these vulnerabilities to prevent supply chain compromises on PyPI.
In a recent discovery that highlights the vulnerability of open-source software, cybersecurity researchers at ReversingLabs have identified potentially exploitable code in legacy Python packages. The investigation focuses on a bootstrap script used by popular build and deployment automation tools to initialize Buildout environments. This script has been known to fetch and execute an installation script for the Distribute package from python-distribute.org, a domain that has been up for sale since 2014.
The idea behind adding this feature was to instruct the bootstrap script to download and install the Distribute package instead of the older Setuptools package. However, as revealed by ReversingLabs, the features from Distribute were integrated back into Setuptools in 2013, rendering Distribute obsolete. Despite its removal, the issue persists due to several affected packages still shipping vulnerable code.
One such example includes the slapos.core package, which continues to ship the vulnerable code and is also included in the development and maintenance version of Tornado. This poses a significant risk for users who may inadvertently run code that triggers the execution of the bootstrap script when they install or update these packages.
The vulnerability arises from the fact that the domain used by the bootstrap script – python-distribute.org – has been up for sale since 2014, which increases the likelihood of an attacker weaponizing this setup. As noted by ReversingLabs, this issue can be attributed to a programming pattern commonly observed in malware exhibiting downloader behavior.
Furthermore, researchers discovered a malicious package named "spellcheckers" that claims to be a tool for checking spelling errors using OpenAI Vision but contains code designed to connect to an external server and download a next-stage payload. This payload executes a remote access trojan (RAT), allowing the attacker to remotely control the user's host via exec(). The malicious package was first uploaded to PyPI on November 15, 2025, by a user named leo636722 and has been downloaded 955 times.
In light of this finding, ReversingLabs emphasizes the importance of addressing these vulnerabilities to prevent potential supply chain compromises on the Python Package Index (PyPI). The cybersecurity company suggests that developers take necessary precautions when running legacy bootstrap scripts or installing affected packages to mitigate the risk of an attacker exploiting this vulnerability for malicious purposes.
As a reminder, the threat of domain takeover is not theoretical. A notable example from 2023 demonstrated how an attacker seized control of an unclaimed cloud resource hosted at fsevents-binaries.s3-us-west-2.amazonaws.com to push malicious executables to users installing certain versions of the npm package fsevents (CVE-2023-45311, CVSS score: 9.8).
Related Information:
https://www.ethicalhackingnews.com/articles/Legacy-Python-Bootstrap-Scripts-Exposed-Unveiling-the-Domain-Takeover-Risk-ehn.shtml
https://thehackernews.com/2025/11/legacy-python-bootstrap-scripts-create.html
Published: Fri Nov 28 11:00:58 2025 by llama3.2 3B Q4_K_M
