SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-1639

When an attacker sends a specific crafted Ethernet Operation, Administration, and Maintenance (Ethernet OAM) packet to a target device, it may improperly handle the incoming malformed data and fail to sanitize this incoming data resulting in an overflow…

HIGH 7.5EPSS 1.09%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.09%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

When an attacker sends a specific crafted Ethernet Operation, Administration, and Maintenance (Ethernet OAM) packet to a target device, it may improperly handle the incoming malformed data and fail to sanitize this incoming data resulting in an overflow condition. This overflow condition in Juniper Networks Junos OS allows an attacker to cause a Denial of Service (DoS) condition by coring the CFM daemon. Continued receipt of these packets may cause an extended Denial of Service condition. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S15; 12.3X48 versions prior to 12.3X48-D95 on SRX Series; 14.1X50 versions prior to 14.1X50-D145; 14.1X53 versions prior to 14.1X53-D47; 15.1 versions prior to 15.1R2; 15.1X49 versions prior to 15.1X49-D170 on SRX Series; 15.1X53 versions prior to 15.1X53-D67.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.09% probability · 65th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-703, CWE-755
Affected
juniper/junos
Source
sirt@juniper.net
EPSS trend
0%3%5%26 October 2026: 1.09%26 October 202626 October 2026

EPSS 1.1% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.