CVE-2020-1625 Junos OS: Kernel memory leak in virtual-memory due to interface flaps
Kernel memory leak in Junos OS causes extended denial of service when IRB interfaces flap, requiring monitoring and patching by network administrators.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2020-1625?
CVE-2020-1625 is a medium-severity denial of service vulnerability in Juniper Junos, published on 8 Apr 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
The kernel memory usage represented as "temp" via 'show system virtual-memory' may constantly increase when Integrated Routing and Bridging (IRB) is configured with multiple underlay physical interfaces, and one interface flaps. This memory leak can affect running daemons (processes), leading to an extended Denial of Service (DoS) condition. Usage of "temp" virtual memory, shown here by a constantly increasing value of outstanding Requests, can be monitored by executing the 'show system virtual-memory' command as shown below: user@junos> show system virtual-memory |match "fpc|type|temp" fpc0: -------------------------------------------------------------------------- Type InUse MemUse HighUse Requests Size(s) temp 2023 431K - 10551 16,32,64,128,256,512,1024,2048,4096,65536,262144,1048576,2097152,4194304,8388608 fpc1: -------------------------------------------------------------------------- Type InUse MemUse HighUse Requests Size(s) temp 2020 431K - 6460 16,32,64,128,256,512,1024,2048,4096,65536,262144,1048576,2097152,4194304,8388608 user@junos> show system virtual-memory |match "fpc|type|temp" fpc0: -------------------------------------------------------------------------- Type InUse MemUse HighUse Requests Size(s) temp 2023 431K - 16101 16,32,64,128,256,512,1024,2048,4096,65536,262144,1048576,2097152,4194304,8388608 fpc1: -------------------------------------------------------------------------- Type InUse MemUse HighUse Requests Size(s) temp 2020 431K - 6665 16,32,64,128,256,512,1024,2048,4096,65536,262144,1048576,2097152,4194304,8388608 user@junos> show system virtual-memory |match "fpc|type|temp" fpc0: -------------------------------------------------------------------------- Type InUse MemUse HighUse Requests Size(s) temp 2023 431K - 21867 16,32,64,128,256,512,1024,2048,4096,65536,262144,1048576,2097152,4194304,8388608 fpc1: -------------------------------------------------------------------------- Type InUse MemUse HighUse Requests Size(s) temp 2020 431K - 6858 16,32,64,128,256,512,1024,2048,4096,65536,262144,1048576,2097152,4194304,8388608 This issue affects Juniper Networks Junos OS: 16.1 versions prior to 16.1R7-S6; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R2-S8, 17.2R3-S3; 17.2X75 versions prior to 17.2X75-D44; 17.3 versions prior to 17.3R2-S5, 17.3R3-S6; 17.4 versions prior to 17.4R2-S5, 17.4R3; 18.1 versions prior to 18.1R3-S7; 18.2 versions prior to 18.2R2-S5, 18.2R3; 18.2X75 versions prior to 18.2X75-D33, 18.2X75-D411, 18.2X75-D420, 18.2X75-D60; 18.3 versions prior to 18.3R1-S5, 18.3R2-S3, 18.3R3; 18.4 versions prior to 18.4R2-S2, 18.4R3; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S3, 19.2R2. This issue does not affect Juniper Networks Junos OS 12.3 and 15.1.
Which versions are affected by CVE-2020-1625?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2020-1625?
No fix has been published for CVE-2020-1625 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2020-1625 being exploited?
There is no known exploitation of CVE-2020-1625 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-7w5f-39wq-4475.