CVE-2020-1024 in SharePoint Enterprise Server
Summary
by MITRE
A remote code execution vulnerability exists in Microsoft SharePoint when the software fails to check the source markup of an application package, aka 'Microsoft SharePoint Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2020-1023, CVE-2020-1102.
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Analysis
by VulDB Data Team • 10/16/2020
The vulnerability identified as CVE-2020-1024 represents a critical remote code execution flaw within Microsoft SharePoint software systems. This weakness stems from insufficient validation mechanisms that fail to properly examine the source markup of application packages before processing them. The vulnerability specifically affects SharePoint Server versions that do not adequately sanitize or verify the contents of packages being installed or deployed within the platform. Security researchers have classified this issue as a significant threat due to its remote exploitation potential, allowing attackers to execute arbitrary code on affected systems without requiring authentication. The flaw exists in the application package handling mechanism where SharePoint fails to perform proper source markup validation, creating an attack surface that can be exploited by malicious actors to gain unauthorized access to server environments. This vulnerability impacts organizations relying on SharePoint for document management, collaboration, and web application hosting, making it particularly dangerous for enterprise environments where SharePoint serves as a central platform for business operations.
The technical root cause of CVE-2020-1024 aligns with CWE-20, which describes improper input validation, and CWE-94, which addresses external control of code generation or execution. The vulnerability manifests when SharePoint processes application packages that contain malicious markup or code within their source files. Attackers can craft specially designed package files that bypass the normal validation checks, allowing malicious code to execute within the SharePoint environment with the privileges of the application pool account. This flaw operates at the application layer and can be exploited through web-based attack vectors, making it particularly dangerous for organizations that allow users to upload or deploy custom applications within SharePoint. The vulnerability does not require user interaction for exploitation, as it can be triggered through automated web requests, and the attack can be performed from remote locations without physical access to the target system. The lack of proper source markup verification creates a path for attackers to inject malicious payloads that can then be executed in the context of the SharePoint server, potentially leading to complete system compromise.
The operational impact of CVE-2020-1024 extends far beyond simple code execution, as it provides attackers with the ability to establish persistent access to SharePoint environments and potentially move laterally within network infrastructures. Organizations using SharePoint for collaboration and document management face severe risks when this vulnerability is exploited, as attackers can gain access to sensitive business documents, user credentials, and internal system information. The vulnerability can be leveraged to deploy additional malware, establish backdoors, or create command and control channels that persist even after initial exploitation attempts. Security teams must consider the potential for data exfiltration, system compromise, and disruption of business operations when evaluating the impact of this vulnerability. The attack surface is particularly concerning for organizations that use SharePoint for external collaboration, as the vulnerability can be exploited by threat actors without requiring any legitimate user credentials. Additionally, the vulnerability may be combined with other exploits or used as a stepping stone for more sophisticated attacks targeting the broader enterprise infrastructure.
Organizations should implement immediate mitigations including applying Microsoft security patches and updates released in response to this vulnerability, as well as implementing network segmentation and access controls to limit exposure. The recommended approach involves disabling the ability to upload or deploy custom application packages when possible, implementing strict content validation procedures, and monitoring for suspicious activity related to SharePoint package installations. Security professionals should also consider deploying web application firewalls and intrusion detection systems to monitor for exploitation attempts targeting this specific vulnerability. The implementation of principle of least privilege access controls for SharePoint applications, combined with regular security assessments and penetration testing, can help reduce the risk of successful exploitation. Organizations should also maintain comprehensive backup and recovery procedures to ensure rapid restoration of services in case of successful exploitation. Due to the nature of this vulnerability and its potential for lateral movement within networks, enterprises should conduct thorough security audits of their SharePoint environments and implement monitoring solutions specifically designed to detect anomalous package deployment activities. The vulnerability also highlights the importance of maintaining current security hygiene practices and ensuring that all software components within SharePoint environments are regularly updated to address known security issues.