CVE-2020-1662
📋 TL;DR
This vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows remote attackers to cause a denial of service by crashing the routing process daemon (RPD) through BGP session flapping. Only devices with both BGP damping and accepted-prefix-limit configurations are affected. The crash triggers an automatic RE switchover, disrupting network routing.
💻 Affected Systems
- Juniper Networks Junos OS
- Juniper Networks Junos OS Evolved
📦 What is this software?
Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →Junos by Juniper
Junos OS is Juniper Networks' flagship network operating system running on enterprise routers, switches, security appliances, and data center infrastructure worldwide. Deployed across telecommunications providers, ISPs, cloud service providers, financial institutions, and large enterprises, Junos po...
Learn more about Junos →⚠️ Risk & Real-World Impact
Worst Case
Sustained BGP session flapping from a malicious peer causes repeated RPD crashes and RE switchovers, leading to extended routing instability and network outages.
Likely Case
Accidental or misconfigured BGP peers cause occasional RPD crashes during prefix-limit threshold events, resulting in brief routing disruptions and automatic recovery.
If Mitigated
With proper prefix limits and monitoring, impact is limited to occasional log messages without service disruption.
🎯 Exploit Status
Exploitation requires ability to flap BGP sessions as a configured peer. No authentication needed beyond BGP peer establishment.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Junos OS: 17.3R3-S8, 17.4R2-S10, 17.4R3-S2, 18.1R3-S10, 18.2R3-S4, 18.2X75-D53, 18.2X75-D65, 18.3R2-S4, 18.3R3-S2, 18.4R2-S5, 18.4R3-S2, 19.1R2-S2, 19.1R3-S1, 19.2R1-S5, 19.2R2, 19.3R2-S3, 19.3R3, 19.4R1-S3, 19.4R2, 20.1R1-S2, 20.1R2. Junos OS Evolved: 20.1R2-EVO.
Vendor Advisory: https://kb.juniper.net/JSA11059
Restart Required: Yes
Instructions:
1. Check current version with 'show version'. 2. Download appropriate fixed version from Juniper support. 3. Install using 'request system software add' or similar upgrade command. 4. Reboot device after installation.
🔧 Temporary Workarounds
Disable BGP Damping
allRemove BGP damping configuration to eliminate the vulnerable condition
delete protocols bgp damping
Remove Prefix Limits
allRemove accepted-prefix-limit configurations from BGP peers
delete protocols bgp group <group-name> neighbor <ip-address> family inet6-unicast prefix-limit maximum
delete protocols bgp group <group-name> neighbor <ip-address> family inet-unicast prefix-limit maximum
🧯 If You Can't Patch
- Implement strict BGP prefix filtering and route validation
- Monitor BGP sessions and prefix counts closely for abnormal behavior
🔍 How to Verify
Check if Vulnerable:
Check if BGP damping and prefix limits are configured: 'show configuration protocols bgp damping' and 'show configuration protocols bgp | display set | match prefix-limit'Check Version:
show version | match JunosVerify Fix Applied:
After patching, verify version is fixed: 'show version | match Junos' and test BGP session flapping with prefix limits📡 Detection & Monitoring
Log Indicators:
- %DAEMON-4-BGP_PREFIX_THRESH_EXCEEDED
- %DAEMON-3-BGP_CEASE_PREFIX_LIMIT_EXCEEDED
- RPD crashed on master RE
- mastership_relinquish_on_process_exit
Network Indicators:
- Frequent BGP session resets
- Unusual prefix count fluctuations
- Routing table instability
SIEM Query:
source="*/var/log/messages*" AND ("BGP_PREFIX_THRESH_EXCEEDED" OR "BGP_CEASE_PREFIX_LIMIT_EXCEEDED" OR "RPD crashed")