OpenProject is an open-source, web-based project management software. Versions prior to 16.6.6 and 17.0.2 have an arbitrary file write vulnerability in OpenProject’s repository diff download endpoint (/projects/:project_id/repository/diff.diff) when rendering a single revision via git show. By supplying a specially crafted rev value (for example, rev=--output=/tmp/poc.txt), an attacker can inject git show command-line options. When OpenProject executes the SCM command, Git interprets the attacker-controlled rev as an option and writes the output to an attacker-chosen path. As a result, any user with the :browse_repository permission on the project can create or overwrite arbitrary files that the OpenProject process user is permitted to write. The written contents consist of git show output (commit metadata and patch), but overwriting application or configuration files still leads to data loss and denial of service, impacting integrity and availability. The issue has been fixed in OpenProject 17.0.2 and 16.6.6.
Weakness
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Openproject | Openproject | * | 16.6.6 (excluding) |
| Openproject | Openproject | 17.0.0 (including) | 17.0.2 (excluding) |
Extended Description
Many protocols and products have their own custom command language. While OS or shell command strings are frequently discovered and targeted, developers may not realize that these other command languages might also be vulnerable to attacks.
Potential Mitigations
- Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
- When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
- Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/136.html
- https://cwe.mitre.org/data/definitions/15.html
- https://cwe.mitre.org/data/definitions/183.html
- https://cwe.mitre.org/data/definitions/248.html
- https://cwe.mitre.org/data/definitions/40.html
- https://cwe.mitre.org/data/definitions/43.html
- https://cwe.mitre.org/data/definitions/75.html
- https://cwe.mitre.org/data/definitions/76.html