Skip to main content

Junos CVE-2020-1653

HIGH
Improper Handling of Invalid Use of Special Elements (CWE-159)
2020-07-17 sirt@juniper.net
7.5
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Special element handling
Impact

CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required.

Exploit ScenarioDerived

This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the high-severity affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 1.6% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAI

On Juniper Networks Junos OS devices, a stream of TCP packets sent to the Routing Engine (RE) may cause mbuf leak which can lead to Flexible PIC Concentrator (FPC) crash or the system to crash and. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified under CWE-159. On Juniper Networks Junos OS devices, a stream of TCP packets sent to the Routing Engine (RE) may cause mbuf leak which can lead to Flexible PIC Concentrator (FPC) crash or the system to crash and restart (vmcore). This issue can be trigged by IPv4 or IPv6 and it is caused only by TCP packets. This issue is not related to any specific configuration and it affects Junos OS releases starting from 17.4R1. However, this issue does not affect Junos OS releases prior to 18.2R1 when Nonstop active routing (NSR) is configured [edit routing-options nonstop-routing]. The number of mbufs is platform dependent. The following command provides the number of mbufs counter that are currently in use and maximum number of mbufs that can be allocated on a platform: user@host> show system buffers 2437/3143/5580 mbufs in use (current/cache/total) Once the device runs out of mbufs, the FPC crashes or the vmcore occurs and the device might become inaccessible requiring a manual restart.4 versions prior to 17.4R2-S11, 17.4R3-S2; 18.1 versions prior to 18.1R3-S10; 18.2 versions prior to 18.2R2-S7, 18.2R3-S5; 18.2X75 versions prior to 18.2X75-D41, 18.2X75-D420.12, 18.2X75-D51, 18.2X75-D60, 18.2X75-D34; 18.3 versions prior to 18.3R2-S4, 18.3R3-S2; 18.4 versions prior to 18.4R1-S7, 18.4R2-S4, 18.4R3-S1; 19.1 versions prior to 19.1R1-S5, 19.1R2-S1, 19.1R3; 19.2 versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2-S3, 19.3R3; 19.4 versions prior to 19.4R1-S2, 19.4R2. Versions of Junos OS prior to 17.4R1 are unaffected by this vulnerability. Affected products include: Juniper Junos. Version information: prior to 18.2.

Know when Junos gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionNVD

On Juniper Networks Junos OS devices, a stream of TCP packets sent to the Routing Engine (RE) may cause mbuf leak which can lead to Flexible PIC Concentrator (FPC) crash or the system to crash and restart (vmcore). This issue can be trigged by IPv4 or IPv6 and it is caused only by TCP packets. This issue is not related to any specific configuration and it affects Junos OS releases starting from 17.4R1. However, this issue does not affect Junos OS releases prior to 18.2R1 when Nonstop active routing (NSR) is configured [edit routing-options nonstop-routing]. The number of mbufs is platform dependent. The following command provides the number of mbufs counter that are currently in use and maximum number of mbufs that can be allocated on a platform: user@host> show system buffers 2437/3143/5580 mbufs in use (current/cache/total) Once the device runs out of mbufs, the FPC crashes or the vmcore occurs and the device might become inaccessible requiring a manual restart. This issue affects Juniper Networks Junos OS 17.4 versions prior to 17.4R2-S11, 17.4R3-S2; 18.1 versions prior to 18.1R3-S10; 18.2 versions prior to 18.2R2-S7, 18.2R3-S5; 18.2X75 versions prior to 18.2X75-D41, 18.2X75-D420.12, 18.2X75-D51, 18.2X75-D60, 18.2X75-D34; 18.3 versions prior to 18.3R2-S4, 18.3R3-S2; 18.4 versions prior to 18.4R1-S7, 18.4R2-S4, 18.4R3-S1; 19.1 versions prior to 19.1R1-S5, 19.1R2-S1, 19.1R3; 19.2 versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2-S3, 19.3R3; 19.4 versions prior to 19.4R1-S2, 19.4R2. Versions of Junos OS prior to 17.4R1 are unaffected by this vulnerability.

Threat Intelligence Overview

EPSS Score
1.6%
Top 27% exploitable
Data Quality
2 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 1.6%
Patch available No
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact· derived
Medium

Priority Score

40
Low Medium High Critical
KEV: 0
EPSS: +2
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)NVD

cpe:2.3:o:juniper:junos:17.4:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r1-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r1-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r1-s4:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r1-s5:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r1-s6:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r1-s7:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r2-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r2-s10:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r2-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r2-s3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r2-s4:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r2-s5:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r2-s6:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r2-s7:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r2-s8:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r2-s9:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:17.4:r3:*:*:*:*:*:*
+ 84 more

More in Junos

View all
CVE-2016-1285 MEDIUM
6.8 Mar 09

named in ISC BIND 9.x before 9.9.8-P4 and 9.10.x before 9.10.3-P4 does not properly handle DNAME records when parsing fe

CVE-2016-1286 HIGH
8.6 Mar 09

named in ISC BIND 9.x before 9.9.8-P4 and 9.10.x before 9.10.3-P4 allows remote attackers to cause a denial of service (

CVE-2025-21590 MEDIUM
6.7 Mar 12

A security vulnerability in An Improper (CVSS 6.7) that allows a local attacker with high privileges. Risk factors: acti

CVE-2023-36845 CRITICAL POC
9.8 Aug 17

A PHP External Variable Modification vulnerability in J-Web of Juniper Networks Junos OS on EX Series and SRX Series all

CVE-2013-6618 CRITICAL POC
9.0 Nov 05

jsdm/ajax/port.php in J-Web in Juniper Junos before 10.4R13, 11.4 before 11.4R7, 12.1 before 12.1R5, 12.2 before 12.2R3,

CVE-2014-6380 HIGH POC
7.8 Oct 14

Juniper Junos 11.4 before R11, 12.1 before R9, 12.1X44 before D30, 12.1X45 before D20, 12.1X46 before D15, 12.1X47 befor

CVE-2021-0253 HIGH POC
7.8 Apr 22

NFX Series devices using Juniper Networks Junos OS are susceptible to a local command execution vulnerability thereby al

CVE-2021-0252 HIGH POC
7.8 Apr 22

NFX Series devices using Juniper Networks Junos OS are susceptible to a local code execution vulnerability thereby allow

CVE-2019-0053 HIGH POC
7.8 Jul 11

Insufficient validation of environment variables in the telnet client supplied in Junos OS can lead to stack-based buffe

CVE-2023-22415 HIGH POC
7.5 Jan 13

An Out-of-Bounds Write vulnerability in the H.323 ALG of Juniper Networks Junos OS allows an unauthenticated, network-ba

CVE-2022-22223 HIGH POC
7.5 Oct 18

On QFX10000 Series devices using Juniper Networks Junos OS when configured as transit IP/MPLS penultimate hop popping (P

CVE-2022-22209 HIGH POC
7.5 Jul 20

A Missing Release of Memory after Effective Lifetime vulnerability in the kernel of Juniper Networks Junos OS allows an

References

Advisories & patches

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy