An Improper Validation of Specified Index, Position, or Offset in Input vulnerability in the Connectivity Fault Management(CFM) module of Juniper Networks Junos OS on MX Series(except MPC10, MPC11 and LC9600) allows an adjacent attacker on the local broadcast domain to cause a Denial of Service(DoS).
Upon receiving a malformed CFM packet, the MPC crashes. Continued receipt of these packets causes a sustained denial of service. This issue can only be triggered when CFM hasn't been configured.
This issue affects:
Juniper Networks Junos OS
versions prior to 19.1R3-S10 on MX Series;
19.2 versions prior to 19.2R3-S7 on MX Series;
19.3 versions prior to 19.3R3-S8 on MX Series;
19.4 versions prior to 19.4R3-S12 on MX Series;
20.1 version 20.1R1 and later versions on MX Series;
20.2 versions prior to 20.2R3-S7 on MX Series;
20.3 version 20.3R1 and later versions on MX Series;
20.4 versions prior to 20.4R3-S7 on MX Series;
21.1 versions prior to 21.1R3-S5 on MX Series;
21.2 versions prior to 21.2R3-S4 on MX Series;
21.3 versions prior to 21.3R3-S4 on MX Series;
21.4 versions prior to 21.4R3-S3 on MX Series;
22.1 versions prior to 22.1R3-S2 on MX Series;
22.2 versions prior to 22.2R3 on MX Series;
22.3 versions prior to 22.3R2, 22.3R3 on MX Series;
22.4 versions prior to 22.4R2 on MX Series.
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
This issue was seen during production usage.
This issue has been assigned CVE-2023-36850.
The following software releases have been updated to resolve this specific issue: 19.1R3-S10, 19.2R3-S7, 19.4R3-S12, 20.2R3-S7, 20.4R3-S7, 21.1R3-S5, 21.2R3-S4, 21.3R3-S4, 21.4R3-S3, 22.1R3-S2, 22.2R3, 22.3R2, 22.3R3, 22.4R2, 23.1R1, and all subsequent releases.
This issue is being tracked as 1700176
Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).
There are no known workarounds for this issue.
2023-07-12: Initial Publication