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2022-01 Security Bulletin: MX Series and SRX series: Flowd core observed if the SIP ALG is enabled and a specific Session Initiation Protocol (SIP) packet is received (CVE-2022-22178)



Article ID: JSA11284 SECURITY_ADVISORIES Last Updated: 12 Jan 2022Version: 1.0
Product Affected:
This issue affects Junos OS 20.4, 21.1, 21.2, 21.3. Affected platforms: MX Series, SRX series.

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 alg 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.
Software releases or updates are available for download at
Modification History:
2022-01-12: Initial Publication.
CVSS Score:
7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Severity Level:
Severity Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

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