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2019-10 Security Bulletin: Junos OS: SRX Series: An attacker may cause flowd to crash by sending certain valid SIP traffic to a device with SIP ALG enabled. (CVE-2019-0055)

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Product Affected:
This issue affects Junos OS 12.3X48, 15.1X49, 17.3, 17.4. Affected platforms: SRX Series.
A vulnerability in the SIP ALG packet processing service of Juniper Networks Junos OS allows an attacker to cause a Denial of Service (DoS) to the device by sending specific types of valid SIP traffic to the device. In this case, the flowd process crashes and generates a core dump while processing SIP ALG traffic.

Continued receipt of these valid SIP packets will result in a sustained Denial of Service (DoS) condition.

This issue affects:

Juniper Networks Junos OS:

12.3X48 versions prior to 12.3X48-D61, 12.3X48-D65 on SRX Series;

15.1X49 versions prior to 15.1X49-D130 on SRX Series;

17.3 versions prior to 17.3R3 on SRX Series;

17.4 versions prior to 17.4R2 on SRX Series.

This issue only affects SRX Series devices where SIP ALG is enabled.

The following minimum configuration is required:

set security 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-2019-0055.

The following software releases have been updated to resolve this specific issue: 12.3X48-D61, 12.3X48-D65, 15.1X49-D130, 17.3R3, 17.4R2, 18.1R1, and all subsequent releases.

This issue is being tracked as PR 1329170 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).


Disable SIP ALG if this is not needed, otherwise there are no viable workarounds for this issue.
Software Releases, patches and updates are available at
Modification History:
2019-10-09: Initial Publication.
Related Links:
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."