2018-07 Security Bulletin: Junos OS: Receipt of specially crafted UDP packets over MPLS may bypass stateless IP firewall rules (CVE-2018-0031)

Product Affected:

This issue affects Junos OS 12.1X46, 12.3, 12.3X48, 14.1X53, 15.1, 15.1X49, 15.1X53, 16.1, 16.2, 17.1, 17.2, 17.2X75, 17.3, 17.4, 18.1, 18.2X75.

Problem:

Receipt of specially crafted UDP/IP packets over MPLS may be able to bypass a stateless firewall filter. The crafted UDP packets must be encapsulated and meet a very specific packet format to be classified in a way that bypasses IP firewall filter rules. The packets themselves do not cause a service interruption (e.g. RPD crash), but receipt of a high rate of UDP packets may be able to contribute to a denial of service attack.

This issue only affects processing of transit UDP/IP packets over MPLS, received on an interface with MPLS enabled. TCP packet processing and non-MPLS encapsulated UDP packet processing are unaffected by this issue.

Affected releases are Juniper Networks Junos OS:

12.1X46 versions prior to 12.1X46-D76;
12.3 versions prior to 12.3R12-S10;
12.3X48 versions prior to 12.3X48-D66, 12.3X48-D70;
14.1X53 versions prior to 14.1X53-D47;
15.1 versions prior to 15.1F6-S10, 15.1R4-S9, 15.1R6-S6, 15.1R7;
15.1X49 versions prior to 15.1X49-D131, 15.1X49-D140;
15.1X53 versions prior to 15.1X53-D59 on EX2300/EX3400;
15.1X53 versions prior to 15.1X53-D67 on QFX10K;
15.1X53 versions prior to 15.1X53-D233 on QFX5200/QFX5110;
15.1X53 versions prior to 15.1X53-D471, 15.1X53-D490 on NFX;
16.1 versions prior to 16.1R3-S8, 16.1R4-S9, 16.1R5-S4, 16.1R6-S3, 16.1R7;
16.2 versions prior to 16.2R1-S6, 16.2R2-S5, 16.2R3;
17.1 versions prior to 17.1R1-S7, 17.1R2-S7, 17.1R3;
17.2 versions prior to 17.2R1-S6, 17.2R2-S4, 17.2R3;
17.2X75 versions prior to 17.2X75-D100, 17.2X75-D110;
17.3 versions prior to 17.3R1-S4, 17.3R2-S2, 17.3R3;
17.4 versions prior to 17.4R1-S3, 17.4R2;
18.1 versions prior to 18.1R2;
18.2X75 versions prior to 18.2X75-D5.

Juniper SIRT is not aware of any malicious exploitation of this vulnerability. This issue was discovered during an external security research.

This issue has been assigned CVE-2018-0031.

Solution:

The following software releases have been updated to resolve this specific issue: 12.1X46-D76, 12.3X48-D66, 12.3X48-D70, 14.1X53-D47, 15.1F6-S10, 15.1R4-S9, 15.1R6-S6, 15.1R7, 15.1X49-D131, 15.1X49-D140, 15.1X53-D233, 15.1X53-D471, 15.1X53-D490, 15.1X53-D59, 15.1X53-D67, 16.1R3-S8, 16.1R4-S9, 16.1R5-S4, 16.1R6-S3, 16.1R7, 16.2R1-S6, 16.2R2-S5, 16.2R3, 17.1R1-S7, 17.1R2-S7, 17.1R3, 17.2R1-S6, 17.2R2-S4, 17.2R3, 17.2X75-D100, 17.2X75-D110, 17.3R1-S4, 17.3R2-S2, 17.3R3, 17.4R1-S3, 17.4R2, 18.1R2, 18.2R1, 18.2X75-D5, and all subsequent releases.

This issue is being tracked as PR 1326402 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)

Workaround:

There are no viable workarounds for this issue.

Implementation:

Software Releases, patches and updates are available at https://www.juniper.net/support/downloads/

Modification History:

2018-07-11: Initial Publication

CVSS Score:

5.3 (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)

Severity Level:

Medium

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."

Acknowledgements:

The Juniper SIRT would like to would like to acknowledge and thank Internet2 and The Indiana University GlobalNOC for responsibly disclosing this vulnerability.

Knowledge Base