CVE-2023-36843 : Security Advisory and Response
Discover CVE-2023-36843 affecting Junos OS by Juniper Networks. Learn about the Denial of Service vulnerability, impacted systems, exploitation risks, and mitigation steps.
A detailed overview of CVE-2023-36843 affecting Junos OS and SRX Series devices from Juniper Networks.
Understanding CVE-2023-36843
This CVE describes an Improper Handling of Inconsistent Special Elements vulnerability in the Junos Services Framework of Juniper Networks Junos OS, leading to a Denial of Service (DoS) attack.
What is CVE-2023-36843?
An unauthenticated network-based attacker can exploit this vulnerability to crash the Packet Forwarding Engine (PFE) by sending malformed SSL traffic, affecting devices with Juniper's Advanced Threat Prevention (ATP) Cloud enabled.
The Impact of CVE-2023-36843
The PFE crash results in a Denial of Service condition, requiring a manual restart to recover the affected device. Juniper SIRT has not detected any malicious exploitation of this vulnerability.
Technical Details of CVE-2023-36843
Details on the vulnerability, affected systems, and exploitation mechanism.
Vulnerability Description
Junos OS is vulnerable to an Improper Handling of Inconsistent Special Elements flaw, allowing an attacker to crash the PFE through malformed SSL traffic.
Affected Systems and Versions
Devices running affected Junos OS versions prior to 22.4R3 can be exploited, primarily impacting SRX Series devices.
Exploitation Mechanism
The vulnerability arises from improper handling of special elements within the Junos Services Framework, triggering a crash in the Packet Forwarding Engine upon receipt of malformed SSL traffic.
Mitigation and Prevention
Measures to address the CVE-2023-36843 vulnerability and prevent potential exploitation.
Immediate Steps to Take
Update to the fixed Junos OS versions (20.4R3-S8, 21.2R3-S6, 21.3R3-S5, etc.) or apply the workaround of removing the security-metadata-streaming policy from configurations.
Long-Term Security Practices
Regularly update Junos OS with the latest releases and security patches to mitigate known vulnerabilities and enhance system security.
Patching and Updates
Juniper Networks has released updated software versions to address the CVE-2023-36843 issue, including Junos OS 23.2R1 and subsequent releases.