Cybersecurity researchers have disclosed particulars of a now-patched privilege escalation vulnerability in Google Cloud Platform (GCP) Cloud Run that would have allowed a malicious actor to entry container photos and even inject malicious code.
“The vulnerability might have allowed such an identification to abuse its Google Cloud Run revision edit permissions so as to pull non-public Google Artifact Registry and Google Container Registry photos in the identical account,” Tenable security researcher Liv Matan stated in a report shared with The Hacker Information.
The security shortcoming has been codenamed ImageRunner by the cybersecurity firm. Following accountable disclosure, Google addressed the issue as of January 28, 2025.
Google Cloud Run is a completely managed service for executing containerized purposes in a scalable, serverless surroundings. When the expertise is used to run a service, container photos are retrieved from the Artifact Registry (or Docker Hub) for subsequent deployment by specifying the picture URL.
At concern is the truth that there are particular identities that lack container registry permissions however which have edit permissions on Google Cloud Run revisions.
Every time a Cloud Run service is deployed or up to date, a brand new model is created. And every time a Cloud Run revision is deployed, a service agent account is used to tug the mandatory photos.
“If an attacker features sure permissions inside a sufferer’s undertaking — particularly run.companies.replace and iam.serviceAccounts.actAs permissions — they may modify a Cloud Run service and deploy a brand new revision,” Matan defined. “In doing so, they may specify any non-public container picture inside the similar undertaking for the service to tug.”
What’s extra, the attacker might entry delicate or proprietary photos saved in a sufferer’s registries and even introduce malicious directions that, when executed, could possibly be abused to extract secrets and techniques, exfiltrate delicate information, and even open a reverse shell to a machine beneath their management.
The patch launched by Google now ensures that the person or service account creating or updating a Cloud Run useful resource has express permission to entry the container photos.
“The principal (person or service account) creating or updating a Cloud Run useful resource now wants express permission to entry the container picture(s),” the tech big stated in its launch notes for Cloud Run in January 2025.
“When utilizing Artifact Registry, make sure the principal has the Artifact Registry Reader (roles/artifactregistry.reader) IAM position on the undertaking or repository containing the container picture(s) to deploy.”
Tenable has characterised ImageRunner for example of what it calls Jenga, which arises because of the interconnected nature of varied cloud companies, inflicting security dangers to be handed alongside.
“Cloud suppliers construct their companies on prime of their different current companies,” Matan stated. “If one service will get attacked or is compromised, the opposite ones constructed on prime of it inherit the danger and turn into susceptible as effectively.”
“This state of affairs opens the door for attackers to find novel privilege escalation alternatives and even vulnerabilities, and introduces new hidden dangers for defenders.”
The disclosure comes weeks after Praetorian detailed a number of methods a lower-privilege principal can abuse an Azure digital machine (VM) to realize management over an Azure subscription –
- Execute instructions on an Azure VM related to an administrative managed identification
- Log in to an Azure VM related to an administrative managed identification
- Connect an current administrative user-assigned managed identification to an current Azure VM and execute instructions in that VM
- Create a brand new Azure VM, connect an current administrative managed identification to it, and execute instructions in that VM by utilizing information airplane actions
“After acquiring the Proprietor position for a subscription, an attacker might be able to leverage their broad management over all subscription sources to discover a privilege escalation path to the Entra ID tenant,” security researchers Andrew Chang and Elgin Lee stated.
“This path is based on a compute useful resource within the sufferer subscription with a service principal with Entra ID permissions that will permit it to escalate itself to International Administrator.”
