Skip to content
CVE Tracker
  • Newest CVEsPage
  • Recently added to KEVPage
  • Rising exploitation (EPSS)Page
  • Weekly digestPage
  • StatisticsPage
  • WatchlistPage
  • API documentationPage
  • MCP serverPage
  • Data sourcesPage
  • ChangelogPage
  • AboutPage
  • How it's builtPage
Back

CVE-2020-1653

Junos OS: Kernel crash (vmcore) or FPC crash due to mbuf leak

High7.5EPSS 1.6%
Published
Updated
Reserved
Assigned by
juniper

Description

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.

Scores

CVSS scores of CVE-2020-1653, by who scored it
Scored byCVSSScoreVector
juniperCNA (assigner)3.1High7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVDNVD · Modified3.1High7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (exploitation in 30 days)
1.6% · top 24% of all CVEs (6 Nov 2026)
Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.

Weakness

Affected products

  • Juniper Networks · Junos OS

    • unaffected unspecified – < 17.4R1
    • affected 17.4 – < 17.4R2-S11, 17.4R3-S2
    • affected 18.1 – < 18.1R3-S10
    • affected 18.2 – < 18.2R2-S7, 18.2R3-S5
    • affected 18.2X75 – < 18.2X75-D41, 18.2X75-D420.12, 18.2X75-D51, 18.2X75-D60, 18.2X75-D34
    • affected 18.3 – < 18.3R2-S4, 18.3R3-S2
    • affected 18.4 – < 18.4R1-S7, 18.4R2-S4, 18.4R3-S1
    • affected 19.1 – < 19.1R1-S5, 19.1R2-S1, 19.1R3
    • affected 19.2 – < 19.2R1-S5, 19.2R2
    • affected 19.3 – < 19.3R2-S3, 19.3R3
    • affected 19.4 – < 19.4R1-S2, 19.4R2

What to do

Solution: The following software releases have been updated to resolve this specific issue: 17.4R2-S11, 17.4R3-S2, 18.1R3-S10, 18.2R2-S7, 18.2R3-S5, 18.2X75-D41, 18.2X75-D420.12, 18.2X75-D51, 18.2X75-D60, 18.2X75-D34, 18.3R2-S4, 18.3R3-S2, 18.4R1-S7, 18.4R2-S4, 18.4R3-S1, 19.1R1-S5, 19.1R2-S1, 19.1R3, 19.2R1-S5, 19.2R2, 19.3R2-S3, 19.3R3, 19.4R1-S2, 19.4R2, 20.1R1, and all subsequent releases.

Workaround: There are no viable workarounds for this issue, however having the DDoS feature enabled and using the firewall filter to limit incoming packet towards the RE only from trusted networks and host help to mitigate this issue. The following command can be used to check if DDoS feature is enabled: user@host> show ddos-protection statistics DDOS protection global statistics: Policing on routing engine: Yes <--- must be "Yes" Policing on FPC: Yes Flow detection: Yes <-- must be Yes <snip>

Exploitation: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

References (1)

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

CVE-2020-1653 badge
[![CVE-2020-1653](https://trackcve.app/badge/CVE-2020-1653.svg)](https://trackcve.app/cve/CVE-2020-1653)

Record last updated .