CVE-2016-4921

Junos: IPv6 denial of service vulnerability due to resource exhaustion (CVE-2016-4921)

HIGH

7.5

CVSS Score

Published: October 13, 2017 at 05:00 PM UTC

Updated: June 17, 2026 at 12:48 AM UTC

1 product affected across 1 vendorJunos

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Severity

HIGH7.5

Exploit prediction

EPSS 3%

Description

By flooding a Juniper Networks router running Junos OS with specially crafted IPv6 traffic, all available resources can be consumed, leading to the inability to store next hop information for legitimate traffic. In extreme cases, the crafted IPv6 traffic may result in a total resource exhaustion and kernel panic. The issue is triggered by traffic destined to the router. Transit traffic does not trigger the vulnerability. This issue only affects devices with IPv6 enabled and configured. Devices not configured to process IPv6 traffic are unaffected by this vulnerability. This issue was found during internal product security testing. Juniper SIRT is not aware of any malicious exploitation of this vulnerability. Affected releases are Juniper Networks Junos OS 11.4 prior to 11.4R13-S3; 12.3 prior to 12.3R3-S4; 12.3X48 prior to 12.3X48-D30; 13.3 prior to 13.3R10, 13.3R4-S11; 14.1 prior to 14.1R2-S8, 14.1R4-S12, 14.1R8; 14.1X53 prior to 14.1X53-D28, 14.1X53-D40; 14.1X55 prior to 14.1X55-D35; 14.2 prior to 14.2R3-S10, 14.2R4-S7, 14.2R6; 15.1 prior to 15.1F2-S5, 15.1F5-S2, 15.1F6, 15.1R3; 15.1X49 prior to 15.1X49-D40; 15.1X53 prior to 15.1X53-D57, 15.1X53-D70.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

v < 11.4R13-S3v < 12.3R3-S4v < 12.3X48-D30v < 13.3R10v < 14.1R2-S8v < 14.1X53-D28v < 14.1X55-D35v < 14.2R3-S10v < 15.1F2-S5v < 15.1X49-D40v < 15.1X53-D5711.4 11.4 r1 11.4 r10 11.4 r11 11.4 r12 11.4 r2 11.4 r3 11.4 r4 11.4 r5 11.4 r6 11.4 r7 11.4 r8 11.4 r9 11.4r13 s2 12.3 12.3 r1 12.3 r2 12.3 r3 12.3x48 d10 12.3x48 d15 12.3x48 d25 13.3 13.3 r1 13.3 r2 13.3 r2-s2 13.3 r3 13.3 r4 13.3 r4-s11 13.3 r5 13.3 r6 13.3 r7 13.3 r8 13.3 r9 14.1 14.1 r1 14.1 r2 14.1 r4 14.1 r8 14.1x53 d15 14.1x53 d16 14.1x53 d25 14.1x53 d26 14.1x53 d27 14.1x53 d40 14.1x55 14.1x55 d30 14.2 r1 14.2 r2 14.2 r3 14.2 r4 14.2 r6 15.1 f1 15.1 f2 15.1 f5 15.1 f6 15.1 r3 15.1x49 d10 15.1x49 d20 15.1x49 d30 15.1x49 d35 15.1x53 d20 15.1x53 d21 15.1x53 d25 15.1x53 d30 15.1x53 d32 15.1x53 d33 15.1x53 d34 15.1x53 d50 15.1x53 d51 15.1x53 d52 15.1x53 d55

Affected range stops below 11.4R13-S3, so it looks safe — our inference, not a vendor statement

Affected range stops below 12.3R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 12.3X48-D30, so it looks safe — our inference, not a vendor statement

Affected range stops below 13.3R10, so it looks safe — our inference, not a vendor statement

Affected range stops below 14.1R2-S8, so it looks safe — our inference, not a vendor statement

Affected range stops below 14.1X53-D28, so it looks safe — our inference, not a vendor statement

Affected range stops below 14.1X55-D35, so it looks safe — our inference, not a vendor statement

Affected range stops below 14.2R3-S10, so it looks safe — our inference, not a vendor statement

Affected range stops below 15.1F2-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 15.1X49-D40, so it looks safe — our inference, not a vendor statement

Affected range stops below 15.1X53-D57, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://kb.juniper.net/JSA10762

References (3)

VDB Entryx_refsource_BIDThird Party Advisory

Source: [email protected]

http://www.securityfocus.com/bid/93532

VDB Entryx_refsource_SECTRACKThird Party Advisory

Source: [email protected]

http://www.securitytracker.com/id/1037014

x_refsource_CONFIRMVendor Advisory

Source: [email protected]

https://kb.juniper.net/JSA10762

CVSS

7.5HIGHjuniper

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-399

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