Juniper Network Devices in the Crosshairs: Global Security Threats Uncovered in Thousands of Cases

Sven Gusek / 17.01.2024

In our digitally interconnected world, the reliability of network infrastructures is paramount. The SRX series firewalls and EX series switches from Juniper Networks are particularly vulnerable due to a flaw in the web management interface. This vulnerability allows unauthorized access and poses a serious threat that must be addressed promptly to ensure the protection of critical data and infrastructure.

Critical Security Flaws in Juniper Products

Juniper Networks, a renowned provider of network solutions, has recently reported the discovery of over two dozen predominantly critical security flaws in their products. A particularly severe issue is a vulnerability in the J-Web interface, which allows unauthorized code to be injected. This vulnerability enables attackers to execute control commands on the affected devices, even with root rights, or to cause the devices to fail. The concerning part is that for a successful attack, neither the manipulation of users nor the fulfillment of specific conditions are necessary. The vulnerability, known under the CVE-ID CVE-2024-21591, was rated with 9.8 out of 10 points on the CVSS scale, highlighting its critical nature.

Affected Devices and Recommended Actions

A wide range of JunOS versions are vulnerable, but only on SRX and EX series devices. The list of affected versions is long, ranging from Junos OS 20.4 to Junos OS 22.4. Juniper urgently recommends updating the systems and provides the necessary software patches. For devices where an update is not possible or no more patches are available, Juniper advises disabling the J-Web interface or restricting access to trusted hosts.

Global Impact of the Security Flaws

An online study by Censys has revealed that over 11,000 devices are affected by the vulnerability. Particularly problematic are outdated devices like the SRX110H2-VA, which has not been supported with updates since March 2022. The majority of the J-Web interfaces accessible over the internet were located in Asia, followed by the United States and Germany. The widespread availability and access to these interfaces significantly increase the risk to network infrastructures. The global scope of this issue underscores the need for a swift and comprehensive response to ensure the security and integrity of critical network infrastructures.

The Future of Juniper under New Ownership

The acquisition of Juniper by HPE signals an ambitious step to expand the market share in the network segment and challenge leading competitors like Cisco. However, this strategic development could be overshadowed by the uncovered security vulnerabilities. Critical security flaws not only pose a technical problem but can also impact the trust of customers and investors. Juniper's ability to respond effectively to these challenges will be crucial in securing their market position and strengthening the confidence of stakeholders.


  • Juniper Support Portal discusses an out-of-bounds write vulnerability in the J-Web of Juniper Networks Junos OS SRX Series and EX Series, allowing an unauthenticated, network-based attacker to cause a Denial of Service (DoS) or Remote Code Execution (RCE) and obtain root privileges on the device

  • CSA reports that Juniper Networks has released security updates addressing a critical vulnerability (CVE-2024-21591) in their SRX Series firewalls and EX Series switches, with a CVSS score of 9.8 out of 10

  • Critical Insight mentions the out-of-bounds write vulnerability in J-Web of Juniper Networks Junos OS SRX Series and EX Series, affecting platforms Junos OS versions earlier than 20.4R3-S9

  • The Hacker News covers Juniper Networks' release of updates to fix a critical remote code execution (RCE) vulnerability in its SRX Series firewalls and EX Series switches, tracked as CVE-2024-21591 and rated 9.8 on the CVSS scoring system

  • Help Net Security details Juniper Networks' fix for a critical pre-authentication remote code execution (RCE) vulnerability (CVE-2024-21591) in Junos OS on SRX firewalls and EX switches