A Stack-based Buffer Overflow vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on MX Series and SRX series allows an unauthenticated networked attacker to cause a flowd crash and thereby a Denial of Service (DoS). Continued receipt of these specific packets will cause a sustained Denial of Service condition.

This issue can be triggered by a specific Session Initiation Protocol (SIP) invite packet if the SIP ALG is enabled. Due to this, the PIC will be rebooted and all traffic that traverses the PIC will be dropped.

This issue affects:

Juniper Networks Junos OS

• 20.4 versions prior to 20.4R3-S2;
• 21.1 versions prior to 21.1R2-S1, 21.1R3;
• 21.2 versions prior to 21.2R2;
• 21.3 versions prior to 21.3R2.

This issue does not affect Juniper Networks Junos OS versions prior to 20.4R1.

To be affected the SIP ALG needs to be enabled, either implicitly / by default or by way of configuration. Please verify on SRX with:

user@host> show security alg status | match sip
SIP : Enabled

Please verify on MX whether the following is configured:

[ services ... rule <rule-name> (term <term-name> ) from/match application/application-set <name> ]

where either

a. name = junos-sip or

an application or application-set refers to SIP:

b. [ applications application <name> application-protocol sip ] or

c. [ applications application-set <name> application junos-sip ]

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-2022-22178 .

The following software releases have been updated to resolve this specific issue: 20.4R3-S2, 21.1R2-S1, 21.1R3, 21.2R2, 21.2R3, 21.3R2, 21.4R1, and all subsequent releases.

This issue is being tracked as  1615438 .

There are no viable workarounds for this issue.