CVE-2020-8255 in Pulse Connect Secure
Summary
by MITRE • 10/28/2020
A vulnerability in the Pulse Connect Secure < 9.1R9 admin web interface could allow an authenticated attacker to perform an arbitrary file reading vulnerability is fixed using encrypted URL blacklisting that prevents these messages.
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Analysis
by VulDB Data Team • 11/29/2020
The vulnerability identified as CVE-2020-8255 affects the Pulse Connect Secure appliance version 9.1R9 and earlier, specifically targeting the administrative web interface. This issue represents a critical security flaw that enables authenticated attackers to exploit arbitrary file reading capabilities within the system. The vulnerability stems from insufficient input validation and access control mechanisms within the web interface components that handle file operations. Attackers who have already gained authentication credentials can leverage this weakness to read sensitive files from the underlying operating system, potentially accessing configuration files, user credentials, or other confidential data stored on the server.
The technical implementation of this vulnerability involves the manipulation of URL parameters within the administrative interface to bypass normal file access controls. When the system processes these modified URLs, it fails to properly validate the requested file paths, allowing attackers to traverse the file system and access files outside of the intended application boundaries. This type of vulnerability falls under the CWE-22 category known as "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')", which is a well-documented weakness in web applications where user-supplied input is not properly sanitized before being used in file system operations. The attack vector specifically targets the administrative web interface, making it particularly dangerous as it provides access to privileged system functions and sensitive data.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can enable attackers to gather intelligence about the system configuration, identify potential attack vectors, and potentially escalate privileges within the network. An authenticated attacker with access to the administrative interface can exploit this weakness to read system files that may contain database connection strings, encryption keys, or other sensitive configuration parameters. This information can then be used to launch further attacks against the network infrastructure or to compromise additional systems within the organization's environment. The vulnerability's presence in the administrative interface makes it particularly concerning as it provides attackers with elevated privileges and access to critical system components that should be protected from unauthorized access.
The vendor addressed this vulnerability through the implementation of encrypted URL blacklisting mechanisms that prevent the processing of maliciously crafted file reading requests. This mitigation strategy involves encrypting URL parameters and maintaining a blacklist of known malicious patterns to prevent unauthorized file access attempts. Organizations should ensure that all Pulse Connect Secure appliances are updated to version 9.1R9 or later to remediate this vulnerability. The fix implements proper input validation and access control checks that prevent path traversal attacks by sanitizing user-supplied input and restricting file access to authorized directories only. Security teams should also implement network monitoring to detect suspicious URL patterns that may indicate exploitation attempts, as this vulnerability aligns with techniques described in the ATT&CK framework under the T1078 credential access tactic, specifically targeting legitimate accounts for unauthorized access. Additionally, organizations should conduct regular security assessments to identify similar vulnerabilities in other network infrastructure components and implement comprehensive access control policies to limit the potential impact of such security flaws.