CVE-2020-1683
Junos OS: Memory leak leads to kernel crash (vmcore) due to SNMP polling
- Published
- Updated
- Reserved
- Assigned by
- juniper
Description
On Juniper Networks Junos OS devices, a specific SNMP OID poll causes a memory leak which over time leads to a kernel crash (vmcore). Prior to the kernel crash other processes might be impacted, such as failure to establish SSH connection to the device. The administrator can monitor the output of the following command to check if there is memory leak caused by this issue: user@device> show system virtual-memory | match "pfe_ipc|kmem" pfe_ipc 147 5K - 164352 16,32,64,8192 <-- increasing vm.kmem_map_free: 127246336 <-- decreasing pfe_ipc 0 0K - 18598 32,8192 vm.kmem_map_free: 134582272 This issue affects Juniper Networks Junos OS: 17.4R3; 18.1 version 18.1R3-S5 and later versions prior to 18.1R3-S10; 18.2 version 18.2R3 and later versions prior to 18.2R3-S3; 18.2X75 version 18.2X75-D420, 18.2X75-D50 and later versions prior to 18.2X75-D430, 18.2X75-D53, 18.2X75-D60; 18.3 version 18.3R3 and later versions prior to 18.3R3-S2; 18.4 version 18.4R1-S4, 18.4R2 and later versions prior to 18.4R2-S5, 18.4R3-S1; 19.1 version 19.1R2 and later versions prior to 19.1R2-S2, 19.1R3; 19.2 version 19.2R1 and later versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2-S5, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2. This issue does not affect Juniper Networks Junos OS prior to 17.4R3.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| juniperCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 1.1% · top 35% of all CVEs (6 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Weakness
Affected products
- affected 17.4R3
- unaffected unspecified – < 17.4R3
- affected 18.1R3-S5 – < 18.1*
- affected 18.2R3 – < 18.2*
- affected 18.2X75-D420, 18.2X75-D50 – < 18.2X75*
- affected 18.3R3 – < 18.3*
- affected 18.4R1-S4, 18.4R2 – < 18.4*
- affected 19.1R2 – < 19.1*
- affected 19.2R1 – < 19.2*
- affected 19.3 – < 19.3R2-S5, 19.3R3
- affected 19.4 – < 19.4R1-S3, 19.4R2
What to do
Solution: The following software releases have been updated to resolve this specific issue: Junos OS 17.4R3-S1, 18.1R3-S10, 18.2R3-S3, 18.2X75-D41, 18.2X75-D430, 18.2X75-D53, 18.2X75-D60, 18.3R3-S2, 18.4R2-S5, 18.4R3-S1, 19.1R2-S2, 19.1R3, 19.2R1-S5, 19.2R2, 19.3R2-S5, 19.3R3, 19.4R1-S3, 19.4R2, 20.1R1, and all subsequent releases.
Workaround: Disable SNMP (disabled by default), utilize edge filtering with source-address validation (uRPF, etc.), access control lists (ACLs), and/or SNMPv3 authentication to limit access to the device only from trusted hosts.
Exploitation: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
References (1)
- https://kb.juniper.net/JSA11080 (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2020-1683)Record last updated .