A now-patched important safety flaw impacting Google Cloud Platform (GCP) Composer might have been exploited to realize distant code execution on cloud servers by the use of a provide chain assault approach referred to as dependency confusion.
The vulnerability has been codenamed CloudImposer by Tenable Analysis.
“The vulnerability might have allowed an attacker to hijack an inside software program dependency that Google pre-installs on every Google Cloud Composer pipeline-orchestration instrument,” safety researcher Liv Matan mentioned in a report shared with The Hacker Information.
Dependency confusion (aka substitution assault), which was first documented by safety researcher Alex Birsan in February 2021, refers to a kind of software program provide chain compromise wherein a bundle supervisor is tricked into pulling a malicious bundle from a public repository as a substitute of the meant file of the identical identify from an inside repository.
So, a risk actor might stage a large-scale provide chain assault by publishing a counterfeit bundle to a public bundle repository with the identical identify as a bundle internally developed by corporations and with the next model quantity.
This, in flip, causes the bundle supervisor to unknowingly obtain the malicious bundle from the general public repository as a substitute of the non-public repository, successfully changing the prevailing bundle dependency with its rogue counterpart.
The issue recognized by Tenable is analogous in that it may very well be abused to add a malicious bundle to the Python Bundle Index (PyPI) repository with the identify “google-cloud-datacatalog-lineage-producer-client,” which might then be preinstalled on all Composer cases with elevated permissions.
Whereas Cloud Composer requires that the bundle in query is version-pinned (i.e., model 0.1.0), Tenable discovered that utilizing the “–extra-index-url” argument throughout a “pip set up” command prioritizes fetching the bundle from the general public registry, thereby opening the door to dependency confusion.
Armed with this privilege, attackers might execute code, exfiltrate service account credentials, and transfer laterally within the sufferer’s setting to different GCP providers.
Following accountable disclosure on January 18, 2024, it was mounted by Google in Could 2024 by guaranteeing that the bundle is simply put in from a non-public repository. It has additionally added the additional precaution of verifying the bundle’s checksum as a way to affirm its integrity and validate that it has not been tampered with.
The Python Packaging Authority (PyPA) is alleged to have been conscious of the dangers posed by the “–extra-index-url” argument since at the least March 2018, urging customers to skip utilizing PyPI in circumstances the place the interior bundle must be pulled.
“Packages are anticipated to be distinctive as much as identify and model, so two wheels with the identical bundle identify and model are handled as indistinguishable by pip,” a PyPA member famous on the time. “It is a deliberate function of the bundle metadata, and never prone to change.”
Google, as a part of its repair, now additionally recommends that builders use the “–index-url” argument as a substitute of the “–extra-index-url” argument and that GCP prospects make use of an Artifact Registry digital repository when requiring a number of repositories.
“The ‘–index-url’ argument reduces the danger of dependency confusion assaults by solely looking for packages within the registry that was outlined as a given worth for that argument,” Matan mentioned.
