title: Junos OS: MX Series with MPC10/MPC11: When Suspicious Control Flow Detection (scfd) is enabled and an attacker is sending specific traffic, this causes a memory leak.
description: A Missing Release of Memory after Effective Lifetime vulnerability in the Juniper Networks Junos OS on MX Series platforms with MPC10/MPC11 line cards, allows an unauthenticated adjacent attacker to cause a Denial of Service (DoS). Devices are only vulnerable when the Suspicious Control Flow Detection (scfd) feature is enabled. Upon enabling this specific feature, an attacker sending specific traffic is causing memory to be allocated dynamically and it is not freed. Memory is not freed even after deactivating this feature. Sustained processing of such traffic will eventually lead to an out of memory condition that prevents all services from continuing to function, and requires a manual restart to recover. The FPC memory usage can be monitored using the CLI command "show chassis fpc". On running the above command, the memory of AftDdosScfdFlow can be observed to detect the memory leak. This issue affects Juniper Networks Junos OS on MX Series: All versions prior to 20.2R3-S5; 20.3 version 20.3R1 and later versions.
problem types: CWE-401 Missing Release of Memory after Effective Lifetime
affected:
{
vendor: Juniper Networks
product: Junos OS
versions:
version: unspecified, lessThan: 20.2R3-S5, status: affected, versionType: custom
version: 20.3R1, status: affected, lessThan: 20.3*, versionType: custom
platforms: MX Series
}
metrics:
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
attackVector: NETWORK
attackComplexity: LOW
privilegesRequired: NONE
userInteraction: NONE
scope: UNCHANGED
confidentialityImpact: NONE
integrityImpact: NONE
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
]
exploits: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
solutions: The following software releases have been updated to resolve this specific issue: 20.2R3-S5, 20.4R1, and all subsequent releases.
workarounds: There are no known workarounds for this issue.