CVE-2021-0272 Denial of service in Junos OS
An adjacent attacker can cause a kernel memory leak and subsequent device crash or service degradation by sending specific EVPN-VXLAN packets to Juniper QFX switches.
- 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-2021-0272?
CVE-2021-0272 is a medium-severity denial of service vulnerability in Juniper Junos, published on 22 Apr 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A kernel memory leak in QFX10002-32Q, QFX10002-60C, QFX10002-72Q, QFX10008, QFX10016 devices Flexible PIC Concentrators (FPCs) on Juniper Networks Junos OS allows an attacker to send genuine packets destined to the device to cause a Denial of Service (DoS) to the device. On QFX10002-32Q, QFX10002-60C, QFX10002-72Q devices the device will crash and restart. On QFX10008, QFX10016 devices, depending on the number of FPCs involved in an attack, one more more FPCs may crash and traffic through the device may be degraded in other ways, until the attack traffic stops. A reboot is required to restore service and clear the kernel memory. Continued receipt and processing of these genuine packets will create a sustained Denial of Service (DoS) condition. On QFX10008, QFX10016 devices, an indicator of compromise may be the existence of DCPFE core files. You can also monitor PFE memory utilization for incremental growth: user@qfx-RE:0% cprod -A fpc0 -c "show heap 0" | grep -i ke 0 3788a1b0 3221225048 2417120656 804104392 24 Kernel user@qfx-RE:0% cprod -A fpc0 -c "show heap 0" | grep -i ke 0 3788a1b0 3221225048 2332332200 888892848 27 Kernel This issue affects: Juniper Networks Junos OS on QFX10002-32Q, QFX10002-60C, QFX10002-72Q, QFX10008, QFX10016: 16.1 versions 16.1R1 and above prior to 17.3 versions prior to 17.3R3-S9; 17.4 versions prior to 17.4R3-S2; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S5; 18.3 versions prior to 18.3R3-S3; 18.4 versions prior to 18.4R2-S5, 18.4R3-S4; 19.1 versions prior to 19.1R3-S2; 19.2 versions prior to 19.2R3; 19.3 versions prior to 19.3R3; 19.4 versions prior to 19.4R3; 20.1 versions prior to 20.1R2. This issue does not affect releases prior to Junos OS 16.1R1. This issue does not affect EX Series devices. This issue does not affect Junos OS Evolved.
Weakness: CWE-401
Which versions are affected by CVE-2021-0272?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2021-0272?
No fix has been published for CVE-2021-0272 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-2021-0272 being exploited?
There is no known exploitation of CVE-2021-0272 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-pprp-5vm4-jh25.