Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.5.2-alpha.13 and 8.6.26, the LDAP authentication adapter is vulnerable to LDAP injection. User-supplied input (authData.id) is interpolated directly into LDAP Distinguished Names (DN) and group search filters without escaping special characters. This allows an attacker with valid LDAP credentials to manipulate the bind DN structure and to bypass group membership checks. This enables privilege escalation from any authenticated LDAP user to a member of any restricted group. The vulnerability affects Parse Server deployments that use the LDAP authentication adapter with group-based access control. This vulnerability is fixed in 9.5.2-alpha.13 and 8.6.26.
Weakness
The product constructs all or part of an LDAP query using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended LDAP query when it is sent to a downstream component.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Parse-server | Parseplatform | * | 8.6.26 (excluding) |
| Parse-server | Parseplatform | 9.0.0 (including) | 9.5.2 (excluding) |
| Parse-server | Parseplatform | 9.5.2-alpha1 (including) | 9.5.2-alpha1 (including) |
| Parse-server | Parseplatform | 9.5.2-alpha10 (including) | 9.5.2-alpha10 (including) |
| Parse-server | Parseplatform | 9.5.2-alpha11 (including) | 9.5.2-alpha11 (including) |
| Parse-server | Parseplatform | 9.5.2-alpha12 (including) | 9.5.2-alpha12 (including) |
| Parse-server | Parseplatform | 9.5.2-alpha2 (including) | 9.5.2-alpha2 (including) |
| Parse-server | Parseplatform | 9.5.2-alpha3 (including) | 9.5.2-alpha3 (including) |
| Parse-server | Parseplatform | 9.5.2-alpha4 (including) | 9.5.2-alpha4 (including) |
| Parse-server | Parseplatform | 9.5.2-alpha5 (including) | 9.5.2-alpha5 (including) |
| Parse-server | Parseplatform | 9.5.2-alpha6 (including) | 9.5.2-alpha6 (including) |
| Parse-server | Parseplatform | 9.5.2-alpha7 (including) | 9.5.2-alpha7 (including) |
| Parse-server | Parseplatform | 9.5.2-alpha8 (including) | 9.5.2-alpha8 (including) |
| Parse-server | Parseplatform | 9.5.2-alpha9 (including) | 9.5.2-alpha9 (including) |
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.