Nextcloud RCE via workflow_scripts & workflow_pdf_converter Fixed 24.0.10/25.0.4
CVE-2023-26482 Published on March 30, 2023
Scope of workflow operations is not validated in nextcloud server
Nextcloud server is an open source home cloud implementation. In affected versions a missing scope validation allowed users to create workflows which are designed to be only available for administrators. Some workflows are designed to be RCE by invoking defined scripts, in order to generate PDFs, invoking webhooks or running scripts on the server. Due to this combination depending on the available apps the issue can result in a RCE at the end. It is recommended that the Nextcloud Server is upgraded to 24.0.10 or 25.0.4. Users unable to upgrade should disable app `workflow_scripts` and `workflow_pdf_converter` as a mitigation.
Vulnerability Analysis
CVE-2023-26482 is exploitable with network access, requires user interaction and a small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.
Weakness Type
What is a Shell injection Vulnerability?
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
CVE-2023-26482 has been classified to as a Shell injection vulnerability or weakness.
Products Associated with CVE-2023-26482
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Affected Versions
nextcloud security-advisories:- Version < 24.0.10 is affected.
- Version >= 25.0.0, < 25.0.4 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.