CVE-2020-1981 in PAN-OS
Summary
by MITRE
A predictable temporary filename vulnerability in PAN-OS allows local privilege escalation. This issue allows a local attacker who bypassed the restricted shell to execute commands as a low privileged user and gain root access on the PAN-OS hardware or virtual appliance. This issue affects only PAN-OS 8.1 versions earlier than PAN-OS 8.1.13. This issue does not affect PAN-OS 7.1, PAN-OS 9.0, or later PAN-OS versions.
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Analysis
by VulDB Data Team • 04/13/2024
The vulnerability identified as CVE-2020-1981 represents a critical predictable temporary filename flaw within PAN-OS operating systems that enables local privilege escalation attacks. This issue specifically targets PAN-OS 8.1 versions prior to 8.1.13, creating a significant security risk for organizations utilizing these older versions of the Palo Alto Networks security platform. The vulnerability operates through a fundamental flaw in how temporary files are generated and managed within the system, allowing malicious actors to exploit predictable naming patterns to execute unauthorized commands with elevated privileges.
The technical implementation of this vulnerability stems from improper randomization or predictability in temporary file generation mechanisms within the PAN-OS environment. When a local attacker successfully bypasses the restricted shell protections, they can leverage this predictable filename weakness to manipulate temporary files that are created during normal system operations. This manipulation enables the attacker to execute commands as a low privileged user while simultaneously gaining root access to the underlying hardware or virtual appliance. The flaw essentially creates a race condition or predictable path attack vector where the attacker can anticipate and potentially overwrite or manipulate temporary files that the system creates during normal processing operations.
The operational impact of CVE-2020-1981 extends beyond simple privilege escalation, as it fundamentally compromises the security model of PAN-OS systems. Organizations running affected versions face potential complete system compromise, with attackers able to gain full administrative control over their network security infrastructure. This vulnerability undermines the core security posture of Palo Alto Networks devices, as it allows attackers to bypass multiple layers of system protection and execute arbitrary code with the highest possible privileges. The attack vector is particularly concerning because it requires only a successful bypass of the restricted shell, which may be achievable through various social engineering or exploitation techniques that target the device's administrative interface.
The vulnerability aligns with CWE-377, which addresses insecure temporary file handling and predictable temporary filenames in system software, and represents a clear violation of the principle of least privilege. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and specifically to the use of predictable temporary files for gaining elevated access. Organizations should implement immediate mitigations including upgrading to PAN-OS 8.1.13 or later versions, which contain the necessary patches to address the predictable filename generation issue. Additionally, security teams should conduct thorough assessments of their PAN-OS environments to identify any systems running vulnerable versions and ensure proper access controls remain in place to prevent unauthorized local access that could lead to exploitation of this vulnerability.