CVE-2018-0031

CVE-2018-0031 is a medium-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Description

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; 17.3 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.

Frequently asked questions

What is CVE-2018-0031?
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; 17.3 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.
How severe is CVE-2018-0031?
CVE-2018-0031 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2018-0031 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-0031?
CVE-2018-0031 primarily affects Juniper Junos. In total, 127 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-0031?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-0031 published?
CVE-2018-0031 was published on 2018-07-11 and last updated on 2026-06-17.

References

Affected products (127)

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