CVE-2021-27855 in WARP
Summary
by MITRE • 12/15/2021
FatPipe WARP, IPVPN, and MPVPN software prior to versions 10.1.2r60p91 and 10.2.2r42 allows a remote, authenticated attacker with read-only privileges to grant themselves administrative privileges. Older versions of FatPipe software may also be vulnerable. The FatPipe advisory identifier for this vulnerability is FPSA001.
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Analysis
by VulDB Data Team • 12/18/2021
The vulnerability identified as CVE-2021-27855 represents a critical privilege escalation flaw affecting FatPipe WARP IPVPN and MPVPN software versions prior to 10.1.2r60p91 and 10.2.2r42. This security weakness enables authenticated attackers who initially possess only read-only access to escalate their privileges and assume full administrative control over affected systems. The flaw resides within the software's privilege management mechanisms, specifically in how it handles user session permissions and access control validation. Attackers exploiting this vulnerability can manipulate their existing read-only sessions to gain administrative privileges without requiring additional authentication factors or elevated credentials.
The technical implementation of this vulnerability stems from inadequate input validation and insufficient privilege boundary enforcement within the FatPipe software architecture. When authenticated users interact with the system, the software fails to properly verify that privilege escalation requests originate from legitimate administrative sources. This weakness creates an attack vector where malicious actors can manipulate session tokens or authentication states to bypass normal access controls. The vulnerability is particularly concerning because it requires minimal prerequisites - only a valid read-only account to initiate the attack, making it accessible to both internal threat actors and external attackers who have obtained such credentials through various means.
From an operational impact perspective, this vulnerability compromises the integrity and confidentiality of network infrastructure managed by FatPipe devices. Once attackers achieve administrative privileges, they can modify network configurations, access sensitive data, disable security controls, and potentially establish persistent backdoors within the network. The attack scenario typically involves an authenticated user who can execute commands within their limited scope, then leverages the privilege escalation flaw to gain full administrative access. This allows for comprehensive system compromise, including the ability to view all network traffic, modify routing tables, alter firewall rules, and access all administrative functions of the affected devices.
Organizations utilizing vulnerable FatPipe software versions face significant risk exposure, particularly in environments where read-only access is granted to multiple users or where credential compromise is possible through phishing attacks, credential theft, or other social engineering techniques. The vulnerability's persistence across multiple software versions indicates a fundamental flaw in the privilege management system rather than an isolated incident. Security teams should immediately assess their network infrastructure for affected devices and implement mitigation measures including immediate software updates to patched versions. The vulnerability aligns with CWE-284, which addresses improper access control in software systems, and corresponds to ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' in adversary tactics and techniques.
Mitigation strategies should prioritize immediate deployment of software patches and updates to versions 10.1.2r60p91 and 10.2.2r42 or later, as provided by FatPipe security advisories. Network administrators should also implement additional monitoring controls to detect suspicious authentication patterns and privilege escalation attempts. The implementation of principle of least privilege should be enforced where possible, limiting the number of users with read-only access that could potentially be exploited. Security information and event management systems should be configured to alert on anomalous privilege changes or unusual administrative activities. Additionally, organizations should conduct comprehensive vulnerability assessments to identify other potential access control weaknesses in their network infrastructure and consider implementing network segmentation to limit the blast radius of potential compromises. Regular security audits and penetration testing should be performed to validate the effectiveness of implemented controls and identify additional areas requiring remediation.