Juniper Junos Flaw Allows Full ‘Root’ Access to Attackers

Hackers target Juniper Junos due to its extensive use in business networking, making it a prime target for accessing valuable systems. Its prominence in large organizations means successful breaches can lead to significant data loss or operational disruption, benefiting threat actors.

Cybersecurity researchers recently identified a flaw in Juniper Junos that allows threat actors to gain full ‘root’ access.

Juniper Junos Flaw

Juniper Networks Junos OS Evolved had multiple instances of Improper Neutralization of Special Elements vulnerabilities in its command-line interface. Attackers with low-level permissions could exploit these flaws by manipulating the command parsing mechanism.

These vulnerabilities allow attackers to elevate their privileges by providing unsanitized inputs to the operating system, resulting in ‘root’ access and total control over the targeted machine.

With root access, threat actors can manipulate system settings, access private information, install malware, and use compromised systems for further attacks, compromising the confidentiality and integrity of network infrastructure running impacted Junos OS Evolved versions.

A critical flaw in Junos OS Evolved Command Line Interface (CLI) parsing command options can be exploited by authorized users through crafted arguments. This vulnerability, if exploited, can grant root access to the system’s shell, compromising its integrity.

Although different from CVE-2021-31356, this flaw highlights the challenges of securing sophisticated operating system interfaces against privilege escalation attacks, especially in network infrastructure software.

This issue affects the following Junos OS Evolved versions:

• All versions before 20.4R3-S7-EVO
• 21.2-EVO versions before 21.2R3-S8-EVO
• 21.4-EVO versions before 21.4R3-S7-EVO
• 22.2-EVO versions before 22.2R3-EVO
• 22.3-EVO versions before 22.3R2-EVO
• 22.4-EVO versions before 22.4R2-EVO

Here are the resolved flaws:

• CVE-2024-39520
• CVE-2024-39521
• CVE-2024-39522
• CVE-2024-39523
• CVE-2024-39524

Juniper Networks has released updated Junos OS versions, including 20.4R3-S7-EVO through 23.2R1-EVO and subsequent releases, to address this vulnerability.