CVE-2020-24700 in OX App Suite
Summary
by MITRE • 01/12/2021
OX App Suite through 7.10.3 allows SSRF because GET requests are sent to arbitrary domain names with an initial autoconfig. substring.
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Analysis
by VulDB Data Team • 02/11/2021
The vulnerability CVE-2020-24700 represents a server-side request forgery issue within OX App Suite version 7.10.3 and earlier, which enables attackers to manipulate the application's behavior by forcing it to make HTTP requests to arbitrary domains. This flaw stems from the application's improper handling of autoconfig requests where it accepts and processes domain names without adequate validation or sanitization. The vulnerability specifically manifests when GET requests are initiated to target domains that begin with the autoconfig substring, creating a pathway for malicious actors to exploit the system's trust in its own configuration mechanisms.
The technical implementation of this vulnerability relies on the application's failure to properly validate user-supplied input during the autoconfiguration process. When the system encounters a request containing the autoconfig prefix, it automatically attempts to resolve and connect to the specified domain without sufficient verification of the target's legitimacy or the request's intent. This behavior creates a fundamental trust issue where the application acts as an unwitting proxy for external requests, potentially exposing internal network resources or sensitive systems that might be reachable from the application server's network context.
From an operational perspective, this vulnerability poses significant risks to organizations using OX App Suite as their email and collaboration platform. Attackers can leverage this flaw to perform reconnaissance activities by directing the application to internal services that would otherwise be protected by network segmentation. The impact extends beyond simple information gathering, as it could potentially enable further exploitation attempts including credential theft, data exfiltration, or lateral movement within the network. The vulnerability's classification aligns with CWE-918, which specifically addresses server-side request forgery vulnerabilities where applications fetch resources from untrusted sources.
The security implications of CVE-2020-24700 are particularly concerning given that it operates at the application layer and can be exploited through seemingly legitimate user interactions. The attack surface is broad as any user who can influence the autoconfig parameter or initiate requests containing the autoconfig substring could potentially exploit this vulnerability. This makes the flaw especially dangerous in environments where user privileges are not properly restricted or where the application serves as a gateway to internal systems. The vulnerability also relates to ATT&CK technique T1071.004, which covers application layer protocol tunneling, as attackers can use the application to indirectly access network resources.
Mitigation strategies for this vulnerability should focus on implementing strict input validation and sanitization mechanisms that prevent arbitrary domain names from being processed during autoconfig requests. Organizations should deploy network-level restrictions that prevent the application server from accessing internal resources, implement proper access controls for autoconfig functionality, and ensure that all external requests are properly validated through a whitelist approach. Additionally, regular security assessments should be conducted to identify similar trust issues within the application, and the system should be updated to version 7.10.4 or later where this vulnerability has been addressed. The implementation of proper logging and monitoring for autoconfig requests will also aid in detecting potential exploitation attempts and provide valuable forensic data for incident response activities.