CVE-2020-1617
Junos OS: PTX1000 and PTX10000 Series, QFX10000 Series using non-AFT architectures: A specific genuine packet inspected by sFlow will cause a reboot.
- Published
- Updated
- Reserved
- Assigned by
- juniper
Description
This issue occurs on Juniper Networks Junos OS devices which do not support Advanced Forwarding Interface (AFI) / Advanced Forwarding Toolkit (AFT). Devices using AFI and AFT are not exploitable to this issue. An improper initialization of memory in the packet forwarding architecture in Juniper Networks Junos OS non-AFI/AFT platforms which may lead to a Denial of Service (DoS) vulnerability being exploited when a genuine packet is received and inspected by non-AFT/AFI sFlow and when the device is also configured with firewall policers. This first genuine packet received and inspected by sampled flow (sFlow) through a specific firewall policer will cause the device to reboot. After the reboot has completed, if the device receives and sFlow inspects another genuine packet seen through a specific firewall policer, the device will generate a core file and reboot. Continued inspection of these genuine packets will create an extended Denial of Service (DoS) condition. Depending on the method for service restoration, e.g. hard boot or soft reboot, a core file may or may not be generated the next time the packet is received and inspected by sFlow. This issue affects: Juniper Networks Junos OS 17.4 versions prior to 17.4R2-S9, 17.4R3 on PTX1000 and PTX10000 Series, QFX10000 Series; 18.1 versions prior to 18.1R3-S9 on PTX1000 and PTX10000 Series, QFX10000 Series; 18.2X75 versions prior to 18.2X75-D12, 18.2X75-D30 on PTX1000 and PTX10000 Series, QFX10000 Series; 18.2 versions prior to 18.2R3 on PTX1000 and PTX10000 Series, QFX10000 Series; 18.3 versions prior to 18.3R3 on PTX1000 and PTX10000 Series, QFX10000 Series. This issue is not applicable to Junos OS versions before 17.4R1. This issue is not applicable to Junos OS Evolved or Junos OS with Advanced Forwarding Toolkit (AFT) forwarding implementations which use a different implementation of sFlow. The following example information is unrelated to this issue and is provided solely to assist you with determining if you have AFT or not. Example: A Junos OS device which supports the use of EVPN signaled VPWS with Flexible Cross Connect uses the AFT implementation. Since this configuration requires support and use of the AFT implementation to support this configuration, the device is not vulnerable to this issue as the sFlow implementation is different using the AFT architecture. For further details about AFT visit the AFI / AFT are in the links below. If you are uncertain if you use the AFI/AFT implementation or not, there are configuration examples in the links below which you may use to determine if you are vulnerable to this issue or not. If the commands work, you are. If not, you are not. You may also use the Feature Explorer to determine if AFI/AFT is supported or not. If you are still uncertain, please contact your support resources.
Timeline
ID reserved
By juniper
- 5 months later
· 5 months later
Published
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
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)
- 1.6% · top 25% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Weakness
- Denial of Service (DoS)
- CWE-665 Improper Initialization (opens in a new tab)All about CWE-665 and its CVEs
Affected products
- affected 17.4 – < 17.4R2-S9, 17.4R3
- affected 18.1 – ≤ 18.1R3-S9
- affected 18.2X75 – < 18.2X75-D12, 18.2X75-D30
- affected 18.2 – < 18.2R3
- affected 18.3 – < 18.3R3
What to do
Solution: The following software releases have been updated to resolve this specific issue: 17.4R2-S9, 17.4R3;18.2X75-D12, 18.2X75-D30, 18.1R3-S9, 18.2R3, 18.3R3, 18.4R1, and all subsequent releases.
Workaround: Discontinue use of firewall policers. Or Discontinue use of sFlow. Or Both of the above. It is not required to discontinue both to mitigate the issue. There are no other available workarounds.
Exploitation: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
References (3)
- https://kb.juniper.net/JSA11000 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/Juniper/AFI (opens in a new tab)x_refsource_MISCx_transferred
- https://www.juniper.net/documentation/en_US/junos/topics/example/example-configuring-vpws-service-with-evpn-signaling-mechanisms.html (opens in a new tab)x_refsource_MISCx_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-2020-1617)Record last updated .