CVE-2022-20798 in Secure Email and Web Manager
Summary
by MITRE • 06/15/2022
A vulnerability in the external authentication functionality of Cisco Secure Email and Web Manager, formerly known as Cisco Security Management Appliance (SMA), and Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass authentication and log in to the web management interface of an affected device. This vulnerability is due to improper authentication checks when an affected device uses Lightweight Directory Access Protocol (LDAP) for external authentication. An attacker could exploit this vulnerability by entering a specific input on the login page of the affected device. A successful exploit could allow the attacker to gain unauthorized access to the web-based management interface of the affected device.
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Analysis
by VulDB Data Team • 06/16/2022
This vulnerability exists within Cisco Secure Email and Web Manager and Cisco Email Security Appliance products where the external authentication mechanism fails to properly validate user credentials when using Lightweight Directory Access Protocol. The flaw represents a critical authentication bypass issue that allows remote attackers to gain administrative access without proper credentials. The vulnerability specifically manifests when the system processes login requests through LDAP authentication, creating a pathway for unauthorized access to the web management interface. According to CWE-287, this vulnerability stems from improper handling of authentication mechanisms, making it a direct descendant of weak authentication controls that have been consistently identified as high-risk security flaws in enterprise systems.
The technical exploitation of CVE-2022-20798 occurs through manipulation of the login page input fields, where specific crafted data can bypass the authentication checks implemented by the LDAP integration. Attackers can leverage this weakness by submitting carefully constructed parameters that exploit the flawed validation logic, effectively circumventing the need for legitimate credentials. The vulnerability demonstrates a classic case of insufficient input validation and authentication flow control, where the system fails to properly sanitize or verify user-provided data before proceeding with authentication decisions. This type of flaw aligns with ATT&CK technique T1078.004 which describes valid accounts usage through compromised credentials, though in this case the attacker gains access through a bypass rather than legitimate credential compromise.
The operational impact of this vulnerability is severe as it provides attackers with full administrative access to critical email security infrastructure, potentially enabling them to modify email policies, access sensitive communications, and exfiltrate data from the organization. Organizations using affected Cisco products face significant risk of data breaches, unauthorized email routing changes, and potential lateral movement within their network infrastructure. The remote nature of the exploit means that attackers can target these systems from anywhere on the internet without requiring physical access or prior network presence. Security teams must consider that this vulnerability could be exploited by automated scanning tools, making it particularly dangerous in environments where multiple devices are exposed to external network traffic. The attack surface extends beyond simple credential theft to include potential privilege escalation and persistent access through the compromised management interface.
Organizations should immediately apply the vendor-provided security patches and updates to address this vulnerability. Network segmentation should be implemented to limit external exposure of management interfaces, while monitoring systems should be configured to detect unusual authentication patterns or login attempts from unexpected sources. Additional mitigations include disabling unnecessary external authentication methods, implementing multi-factor authentication where possible, and conducting thorough network scans to identify all affected devices. Security teams should also review their incident response procedures to ensure readiness for potential exploitation of this vulnerability, considering that the attack could occur without traditional signs of compromise such as credential theft or brute force attempts. The vulnerability highlights the importance of proper authentication flow testing and validation, particularly in systems that integrate with external directory services like LDAP.