CVE-2021-29108 in Portal for ArcGIS
Summary
by MITRE • 10/02/2021
There is an privilege escalation vulnerability in organization-specific logins in Esri Portal for ArcGIS versions 10.9 and below that may allow a remote, authenticated attacker to impersonate another account.
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Analysis
by VulDB Data Team • 10/08/2021
The vulnerability identified as CVE-2021-29108 represents a critical privilege escalation flaw within Esri Portal for ArcGIS versions 10.9 and earlier systems. This security weakness specifically targets the organization-specific login mechanisms that are fundamental to the platform's authentication architecture. The flaw enables remote attackers who have already established authenticated sessions to exploit a design weakness that allows them to assume the identity of other user accounts within the same organization. This type of vulnerability falls under the category of identity impersonation and privilege escalation, which are particularly dangerous because they can bypass traditional access controls and potentially lead to unauthorized data access or system manipulation.
The technical implementation of this vulnerability stems from insufficient validation of user permissions and session management within the portal's authentication subsystem. When users authenticate through the organization-specific login mechanisms, the system fails to properly verify that the requesting user has legitimate authorization to access or impersonate other accounts. This weakness creates a path for attackers to manipulate session tokens or authentication parameters to gain elevated privileges. The vulnerability is particularly concerning because it operates at the authentication layer where proper access controls should be enforced, making it a prime target for attackers seeking to expand their operational capabilities within the system. According to CWE classification, this vulnerability aligns with CWE-285: Improper Authorization, which specifically addresses situations where systems fail to properly enforce access control mechanisms.
The operational impact of CVE-2021-29108 extends beyond simple unauthorized access, as it fundamentally compromises the integrity of the authentication system. Attackers who successfully exploit this vulnerability can potentially access sensitive organizational data, modify user permissions, or even escalate their privileges to administrative levels depending on the system configuration. The remote nature of this attack vector means that exploitation can occur from outside the organization's network perimeter, making traditional network-based security controls less effective against this threat. This vulnerability directly maps to ATT&CK technique T1078: Valid Accounts, as it allows attackers to leverage legitimate user credentials to gain unauthorized access to other accounts within the same organization. Organizations using affected versions of Esri Portal for ArcGIS face significant risk of data breaches, insider threat exploitation, and potential compliance violations due to the unauthorized access capabilities this vulnerability provides.
Mitigation strategies for CVE-2021-29108 primarily focus on immediate patching of affected systems to the latest versions of Esri Portal for ArcGIS where the vulnerability has been addressed. Organizations should also implement enhanced monitoring of authentication events and session management activities to detect potential exploitation attempts. Network segmentation and privileged access controls should be strengthened to limit the blast radius of any successful exploitation. Additionally, security teams should conduct comprehensive audits of user permissions and access controls to identify any potential unauthorized access that may have occurred prior to patching. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches and implementing robust access control mechanisms within enterprise GIS platforms. Organizations should also consider implementing multi-factor authentication and additional verification layers to provide defense-in-depth against similar authentication-related vulnerabilities. Regular security assessments of authentication systems are essential to identify and remediate similar weaknesses before they can be exploited by malicious actors.