CVE-2021-0257 : Vulnerability Insights and Analysis
Discover the impact of CVE-2021-0257 on Juniper MX & EX9200 Series. Learn about the memory leak vulnerability in VPLS with IRB interface, affected systems, and mitigation steps.
Juniper Networks MX Series and EX9200 Series platforms with Trio-based MPCs are prone to a memory leak vulnerability in VPLS with an integrated IRB interface, leading to an out-of-memory condition and potential restart of the MPC.
Understanding CVE-2021-0257
This CVE affects Juniper Networks MX Series and EX9200 Series platforms with specific Trio-based MPCs, causing memory leaks in certain scenarios, potentially resulting in temporary traffic interruption.
What is CVE-2021-0257?
The vulnerability arises in IRB interfaces configured for VPLS instances or Bridge-Domains on affected Juniper Networks devices due to memory leaks, culminating in an out-of-memory situation and potential MPC restarts.
The Impact of CVE-2021-0257
The vulnerability could lead to temporary traffic disruption on affected devices until the MPC is restored, affecting devices running specific Junos OS versions.
Technical Details of CVE-2021-0257
The issue stems from certain Layer 2 network events at CE devices causing memory leaks in MPCs, impacting traffic until MPC restarts. The problem affects various Junos OS versions on specific Juniper platforms.
Vulnerability Description
Events at CE devices can trigger memory leaks in the MPC of PE devices, leading to an out-of-memory scenario and temporary traffic interruptions.
Affected Systems and Versions
Devices running Juniper Networks Junos OS versions 17.3 to 20.3 on MX Series and EX9200 Series platforms with specific Trio-based PFEs are vulnerable to this issue.
Exploitation Mechanism
Juniper SIRT has not detected any malevolent exploitation of this vulnerability.
Mitigation and Prevention
To address this vulnerability, Juniper has released software updates for specific Junos OS versions on affected devices, resolving the memory leak issue.
Immediate Steps to Take
Updating affected Junos OS versions to 17.3R3-S10, 17.4R3-S3, 18.2R3-S7, 18.3R3-S4, 18.4R3-S6, 19.2R3-S2, 19.3R3-S1, 19.4R2-S2, 19.4R3, 20.1R2, 20.2R1-S3, 20.2R2, 20.2R3, 20.3R1-S1, 20.3R2, 20.4R1, or later releases is recommended to mitigate the vulnerability.
Long-Term Security Practices
Regularly updating Junos OS to the latest patched versions and adopting best security practices can enhance system security and mitigate future vulnerabilities.
Patching and Updates
Juniper recommends applying the available software updates to fix the memory leak issue in affected devices running Junos OS.