Vulnerability Database

346,508

Total vulnerabilities in the database

CVE-2021-0272 — juniper / junos

Missing Release of Memory after Effective Lifetime

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.

  • Published: Apr 22, 2021
  • Updated: Nov 16, 2025
  • CVE: CVE-2021-0272
  • Severity: Medium
  • Exploit:

CVSS v3:

  • Severity: Medium
  • Score: 6.5
  • AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v2:

  • Severity: Medium
  • Score: 6.1
  • AV:A/AC:L/Au:N/C:N/I:N/A:C

CWEs:

Software From Fixed in
juniper / junos 16.1-r1 16.1-r1.x
juniper / junos 16.1-r4-s4 16.1-r4-s4.x
juniper / junos 16.1-r4 16.1-r4.x
juniper / junos 16.1-r4-s3 16.1-r4-s3.x
juniper / junos 16.1-r5-s4 16.1-r5-s4.x
juniper / junos 16.1-r6-s1 16.1-r6-s1.x
juniper / junos 16.1-r7 16.1-r7.x
juniper / junos 16.1-r3 16.1-r3.x
juniper / junos 16.1-r5 16.1-r5.x
juniper / junos 16.1-r2 16.1-r2.x
juniper / junos 16.1-r6 16.1-r6.x
juniper / junos 16.1-r4-s9 16.1-r4-s9.x
juniper / junos 16.1-r6-s3 16.1-r6-s3.x
juniper / junos 16.1-r6-s4 16.1-r6-s4.x
juniper / junos 16.1-r6-s6 16.1-r6-s6.x
juniper / junos 16.1-r3-s8 16.1-r3-s8.x
juniper / junos 16.1-r4-s8 16.1-r4-s8.x
juniper / junos 16.1-r3-s10 16.1-r3-s10.x
juniper / junos 16.1-r3-s11 16.1-r3-s11.x
juniper / junos 16.1-r7-s3 16.1-r7-s3.x
juniper / junos 16.1-r7-s4 16.1-r7-s4.x
juniper / junos 16.1-r7-s2 16.1-r7-s2.x
juniper / junos 16.1-r7-s5 16.1-r7-s5.x
juniper / junos 16.1-r4-s12 16.1-r4-s12.x
juniper / junos 16.1-r4-s6 16.1-r4-s6.x
juniper / junos 16.1-r4-s2 16.1-r4-s2.x
juniper / junos 16.1-r7-s6 16.1-r7-s6.x
juniper / junos 16.1-r7-s7 16.1-r7-s7.x
juniper / junos 16.1-r7-s8 16.1-r7-s8.x
juniper / junos 16.2-r2-s10 16.2-r2-s10.x
juniper / junos 16.2 16.2.x
juniper / junos 16.2-r2-s9 16.2-r2-s9.x
juniper / junos 16.2-r1 16.2-r1.x
juniper / junos 16.2-r2-s1 16.2-r2-s1.x
juniper / junos 16.2-r2-s2 16.2-r2-s2.x
juniper / junos 16.2-r2-s6 16.2-r2-s6.x
juniper / junos 16.2-r2-s7 16.2-r2-s7.x
juniper / junos 16.2-r2-s8 16.2-r2-s8.x
juniper / junos 16.2-r1-s6 16.2-r1-s6.x
juniper / junos 16.2-r2-s5 16.2-r2-s5.x
juniper / junos 16.2-r2 16.2-r2.x
juniper / junos 16.2-r3 16.2-r3.x
juniper / junos 17.1-r3 17.1-r3.x
juniper / junos 17.1-r2 17.1-r2.x
juniper / junos 17.1-r1 17.1-r1.x
juniper / junos 17.1-r2-s7 17.1-r2-s7.x
juniper / junos 17.1-r1-s7 17.1-r1-s7.x
juniper / junos 17.1-r2-s1 17.1-r2-s1.x
juniper / junos 17.1-r2-s2 17.1-r2-s2.x
juniper / junos 17.1-r2-s3 17.1-r2-s3.x
juniper / junos 17.1-r2-s4 17.1-r2-s4.x
juniper / junos 17.1-r2-s5 17.1-r2-s5.x
juniper / junos 17.1-r2-s6 17.1-r2-s6.x
juniper / junos 17.1-r2-s8 17.1-r2-s8.x
juniper / junos 17.1 17.1.x
juniper / junos 17.1-r2-s10 17.1-r2-s10.x
juniper / junos 17.1-r2-s9 17.1-r2-s9.x
juniper / junos 17.1-r2-s11 17.1-r2-s11.x
juniper / junos 17.1-r3-s2 17.1-r3-s2.x
juniper / junos 17.1-r3-s1 17.1-r3-s1.x
juniper / junos 17.2-r3-s4 17.2-r3-s4.x
juniper / junos 17.2-r3-s3 17.2-r3-s3.x
juniper / junos 17.2-r2-s11 17.2-r2-s11.x
juniper / junos 17.2-r3-s2 17.2-r3-s2.x
juniper / junos 17.2 17.2.x
juniper / junos 17.2-r1-s8 17.2-r1-s8.x
juniper / junos 17.2-r2-s7 17.2-r2-s7.x
juniper / junos 17.2-r3-s1 17.2-r3-s1.x
juniper / junos 17.2-r1-s4 17.2-r1-s4.x
juniper / junos 17.2-r2-s6 17.2-r2-s6.x
juniper / junos 17.2-r1-s7 17.2-r1-s7.x
juniper / junos 17.2-r1-s2 17.2-r1-s2.x
juniper / junos 17.2-r3 17.2-r3.x
juniper / junos 17.2-r1-s1 17.2-r1-s1.x
juniper / junos 17.2-r1-s3 17.2-r1-s3.x
juniper / junos 17.2-r1-s5 17.2-r1-s5.x
juniper / junos 17.2-r1-s6 17.2-r1-s6.x
juniper / junos 17.2-r2-s4 17.2-r2-s4.x
juniper / junos 17.2-r2 17.2-r2.x
juniper / junos 17.2-r1 17.2-r1.x
juniper / junos 17.3-r2 17.3-r2.x
juniper / junos 17.3-r2-s2 17.3-r2-s2.x
juniper / junos 17.3-r3 17.3-r3.x
juniper / junos 17.3-r1 17.3-r1.x
juniper / junos 17.3-r1-s4 17.3-r1-s4.x
juniper / junos 17.3-r3-s1 17.3-r3-s1.x
juniper / junos 17.3-r3-s2 17.3-r3-s2.x
juniper / junos 17.3-r2-s1 17.3-r2-s1.x
juniper / junos 17.3-r3-s4 17.3-r3-s4.x
juniper / junos 17.3-r3-s5 17.3-r3-s5.x
juniper / junos 17.3-r3-s6 17.3-r3-s6.x
juniper / junos 17.3-r2-s3 17.3-r2-s3.x
juniper / junos 17.3 17.3.x
juniper / junos 17.3-r3-s3 17.3-r3-s3.x
juniper / junos 17.3-r2-s4 17.3-r2-s4.x
juniper / junos 17.3-r1-s1 17.3-r1-s1.x
juniper / junos 17.3-r3-s8 17.3-r3-s8.x
juniper / junos 17.3-r3-s10 17.3-r3-s10.x
juniper / junos 17.3-r3-s7 17.3-r3-s7.x
juniper / junos 17.3-r2-s5 17.3-r2-s5.x
juniper / junos 17.4-r2-s11 17.4-r2-s11.x
juniper / junos 17.4-r3-s1 17.4-r3-s1.x
juniper / junos 17.4-r2-s9 17.4-r2-s9.x
juniper / junos 17.4-r2-s10 17.4-r2-s10.x
juniper / junos 17.4-r2-s8 17.4-r2-s8.x
juniper / junos 17.4-r2-s5 17.4-r2-s5.x
juniper / junos 17.4-r2-s6 17.4-r2-s6.x
juniper / junos 17.4-r2-s7 17.4-r2-s7.x
juniper / junos 17.4-r1-s5 17.4-r1-s5.x
juniper / junos 17.4-r1-s7 17.4-r1-s7.x
juniper / junos 17.4-r1-s4 17.4-r1-s4.x
juniper / junos 17.4 17.4.x
juniper / junos 17.4-r2-s3 17.4-r2-s3.x
juniper / junos 17.4-r2-s4 17.4-r2-s4.x
juniper / junos 17.4-r1-s6 17.4-r1-s6.x
juniper / junos 17.4-r3 17.4-r3.x
juniper / junos 17.4-r2-s1 17.4-r2-s1.x
juniper / junos 17.4-r1-s2 17.4-r1-s2.x
juniper / junos 17.4-r1-s1 17.4-r1-s1.x
juniper / junos 17.4-r2-s2 17.4-r2-s2.x
juniper / junos 17.4-r1-s3 17.4-r1-s3.x
juniper / junos 17.4-r1 17.4-r1.x
juniper / junos 17.4-r2 17.4-r2.x
juniper / junos 18.1-r2 18.1-r2.x
juniper / junos 18.1-r1 18.1-r1.x
juniper / junos 18.1-r3 18.1-r3.x
juniper / junos 18.1-r2-s2 18.1-r2-s2.x
juniper / junos 18.1-r3-s5 18.1-r3-s5.x
juniper / junos 18.1-r3-s4 18.1-r3-s4.x
juniper / junos 18.1-r3-s3 18.1-r3-s3.x
juniper / junos 18.1-r3-s2 18.1-r3-s2.x
juniper / junos 18.1 18.1.x
juniper / junos 18.1-r2-s1 18.1-r2-s1.x
juniper / junos 18.1-r2-s4 18.1-r2-s4.x
juniper / junos 18.1-r3-s1 18.1-r3-s1.x
juniper / junos 18.1-r3-s6 18.1-r3-s6.x
juniper / junos 18.1-r3-s7 18.1-r3-s7.x
juniper / junos 18.1-r3-s10 18.1-r3-s10.x
juniper / junos 18.1-r3-s9 18.1-r3-s9.x
juniper / junos 18.1-r3-s8 18.1-r3-s8.x
juniper / junos 18.2-r3-s2 18.2-r3-s2.x
juniper / junos 18.2-r3-s3 18.2-r3-s3.x
juniper / junos 18.2-r3-s4 18.2-r3-s4.x
juniper / junos 18.2-r2-s7 18.2-r2-s7.x
juniper / junos 18.2-r1-s2 18.2-r1-s2.x
juniper / junos 18.2-r2-s5 18.2-r2-s5.x
juniper / junos 18.2-r2-s6 18.2-r2-s6.x
juniper / junos 18.2-r3-s1 18.2-r3-s1.x
juniper / junos 18.2-r3 18.2-r3.x
juniper / junos 18.2-r2-s3 18.2-r2-s3.x
juniper / junos 18.2-r2-s4 18.2-r2-s4.x
juniper / junos 18.2-r1-s4 18.2-r1-s4.x
juniper / junos 18.2-r1-s5 18.2-r1-s5.x
juniper / junos 18.2-r2 18.2-r2.x
juniper / junos 18.2 18.2.x
juniper / junos 18.2-r2-s1 18.2-r2-s1.x
juniper / junos 18.2-r2-s2 18.2-r2-s2.x
juniper / junos 18.2-r1-s3 18.2-r1-s3.x
juniper / junos 18.2-r1 18.2-r1.x
juniper / junos 18.3-r1-s1 18.3-r1-s1.x
juniper / junos 18.3-r2 18.3-r2.x
juniper / junos 18.3-r1 18.3-r1.x
juniper / junos 18.3-r1-s4 18.3-r1-s4.x
juniper / junos 18.3-r1-s3 18.3-r1-s3.x
juniper / junos 18.3-r1-s2 18.3-r1-s2.x
juniper / junos 18.3 18.3.x
juniper / junos 18.3-r1-s5 18.3-r1-s5.x
juniper / junos 18.3-r2-s1 18.3-r2-s1.x
juniper / junos 18.3-r2-s2 18.3-r2-s2.x
juniper / junos 18.3-r3-s2 18.3-r3-s2.x
juniper / junos 18.3-r2-s4 18.3-r2-s4.x
juniper / junos 18.3-r2-s3 18.3-r2-s3.x
juniper / junos 18.3-r1-s6 18.3-r1-s6.x
juniper / junos 18.3-r3 18.3-r3.x
juniper / junos 18.3-r3-s1 18.3-r3-s1.x
juniper / junos 18.4-r3 18.4-r3.x
juniper / junos 18.4-r2-s3 18.4-r2-s3.x
juniper / junos 18.4-r1-s6 18.4-r1-s6.x
juniper / junos 18.4-r3-s2 18.4-r3-s2.x
juniper / junos 18.4-r3-s1 18.4-r3-s1.x
juniper / junos 18.4-r2-s4 18.4-r2-s4.x
juniper / junos 18.4-r3-s3 18.4-r3-s3.x
juniper / junos 18.4-r1-s7 18.4-r1-s7.x
juniper / junos 18.4-r2 18.4-r2.x
juniper / junos 18.4-r2-s1 18.4-r2-s1.x
juniper / junos 18.4-r2-s2 18.4-r2-s2.x
juniper / junos 18.4-r1-s5 18.4-r1-s5.x
juniper / junos 18.4 18.4.x
juniper / junos 18.4-r1-s1 18.4-r1-s1.x
juniper / junos 18.4-r1-s3 18.4-r1-s3.x
juniper / junos 18.4-r1-s4 18.4-r1-s4.x
juniper / junos 18.4-r1-s2 18.4-r1-s2.x
juniper / junos 18.4-r1 18.4-r1.x
juniper / junos 19.1-r1 19.1-r1.x
juniper / junos 19.1 19.1.x
juniper / junos 19.1-r1-s1 19.1-r1-s1.x
juniper / junos 19.1-r1-s3 19.1-r1-s3.x
juniper / junos 19.1-r1-s2 19.1-r1-s2.x
juniper / junos 19.1-r1-s5 19.1-r1-s5.x
juniper / junos 19.1-r2-s1 19.1-r2-s1.x
juniper / junos 19.1-r3 19.1-r3.x
juniper / junos 19.1-r3-s1 19.1-r3-s1.x
juniper / junos 19.1-r1-s4 19.1-r1-s4.x
juniper / junos 19.1-r2 19.1-r2.x
juniper / junos 19.2-r1-s3 19.2-r1-s3.x
juniper / junos 19.2-r1-s4 19.2-r1-s4.x
juniper / junos 19.2-r1-s5 19.2-r1-s5.x
juniper / junos 19.2-r2-s1 19.2-r2-s1.x
juniper / junos 19.2-r2 19.2-r2.x
juniper / junos 19.2-r1-s1 19.2-r1-s1.x
juniper / junos 19.2-r1-s2 19.2-r1-s2.x
juniper / junos 19.2-r1 19.2-r1.x
juniper / junos 19.2 19.2.x
juniper / junos 19.3 19.3.x
juniper / junos 19.3-r1 19.3-r1.x
juniper / junos 19.3-r2-s5 19.3-r2-s5.x
juniper / junos 19.3-r2-s4 19.3-r2-s4.x
juniper / junos 19.3-r2-s3 19.3-r2-s3.x
juniper / junos 19.3-r2-s2 19.3-r2-s2.x
juniper / junos 19.3-r2 19.3-r2.x
juniper / junos 19.3-r2-s1 19.3-r2-s1.x
juniper / junos 19.3-r1-s1 19.3-r1-s1.x
juniper / junos 19.4-r1 19.4-r1.x
juniper / junos 19.4-r1-s1 19.4-r1-s1.x
juniper / junos 19.4-r1-s2 19.4-r1-s2.x
juniper / junos 19.4-r2 19.4-r2.x
juniper / junos 19.4-r2-s1 19.4-r2-s1.x
juniper / junos 19.4-r2-s2 19.4-r2-s2.x
juniper / junos 19.4-r2-s3 19.4-r2-s3.x
juniper / junos 20.1-r1-s4 20.1-r1-s4.x
juniper / junos 20.1-r1-s1 20.1-r1-s1.x
juniper / junos 20.1-r1-s2 20.1-r1-s2.x
juniper / junos 20.1-r1-s3 20.1-r1-s3.x
juniper / junos 20.1-r1 20.1-r1.x

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.