Junos: IPv6 denial of service vulnerability due to resource exhaustion (CVE-2016-4921)
Published Oct 13, 2017
7.5
HIGHCVSS 3.0
EPSS 2.91%
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 products
-
- Version 11.4 prior to 11.4R13-S3StatusaffectedConstraints-
- Version 12.3 prior to 12.3R3-S4StatusaffectedConstraints-
- Version 12.3X48 prior to 12.3X48-D30StatusaffectedConstraints-
- Version 13.3 prior to 13.3R10, 13.3R4-S11StatusaffectedConstraints-
- Version 14.1 prior to 14.1R2-S8, 14.1R4-S12, 14.1R8StatusaffectedConstraints-
- Version 14.1X53 prior to 14.1X53-D28, 14.1X53-D40StatusaffectedConstraints-
- Version 14.1X55 prior to 14.1X55-D35StatusaffectedConstraints-
- Version 14.2 prior to 14.2R3-S10, 14.2R4-S7, 14.2R6StatusaffectedConstraints-
- Version 15.1 prior to 15.1F2-S5, 15.1F5-S2, 15.1F6, 15.1R3StatusaffectedConstraints-
- Version 15.1X49 prior to 15.1X49-D40StatusaffectedConstraints-
- Version 15.1X53 prior to 15.1X53-D57, 15.1X53-D70StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Juniper Networks | Junos OS | n/a |
|
Configuration 1
- 11.4
- 11.4
- 11.4
- 11.4
- 11.4
- 11.4
- 11.4
- 11.4
- 11.4
- 11.4
- 11.4
- 11.4
- 11.4
- 11.4r13
Configuration 2
Configuration 3
Configuration 4
- 14.1
- 14.1
- 14.1
- 14.1
- 14.1
- 14.1x53
- 14.1x53
- 14.1x53
- 14.1x53
- 14.1x53
- 14.1x53
- 14.1x55
- 14.1x55
Configuration 5
Configuration 6
- 15.1
- 15.1
- 15.1
- 15.1
- 15.1
- 15.1x49
- 15.1x49
- 15.1x49
- 15.1x49
- 15.1x53
- 15.1x53
- 15.1x53
- 15.1x53
- 15.1x53
- 15.1x53
- 15.1x53
- 15.1x53
- 15.1x53
- 15.1x53
- 15.1x53
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
Vendor solution
Limit the exploitable attack surface of critical infrastructure networking equipment. Use access lists or firewall filters to limit access to the router via IPv6 only from trusted, administrative networks or hosts.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AV:N/AC:L/Au:N/C:N/I:N/A:C
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (12 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 2.91% (0.02914) | 86.52th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.91% (0.02914) | 85.16th | v5 (v2026.06.15) |
| Mar 17, 2025 | 1.35% (0.01351) | 78.77th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.31% (0.00314) | 71.10th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.31% (0.00314) | 69.42th | v3 (v2023.03.01) |
| Jun 2, 2023 | 0.31% (0.00314) | 65.87th | v3 (v2023.03.01) |
| Apr 15, 2023 | 0.37% (0.00374) | 68.58th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.35% (0.00354) | 67.54th | v3 (v2023.03.01) |
| Mar 6, 2023 | 0.95% (0.00954) | 36.37th | v2 (v2022.01.01) |
| Sep 2, 2022 | 0.95% (0.00954) | 34.50th | v2 (v2022.01.01) |
| Apr 1, 2022 | 0.95% (0.00954) | 32.50th | v2 (v2022.01.01) |
| Feb 4, 2022 | 0.95% (0.00954) | 16.28th | v2 (v2022.01.01) |
References (3)
- http://www.securityfocus.com/bid/93532 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1037014 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://kb.juniper.net/JSA10762 x_refsource_CONFIRMVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| http://www.securityfocus.com/bid/93532 | vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry | |
| http://www.securitytracker.com/id/1037014 | vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry | |
| https://kb.juniper.net/JSA10762 | x_refsource_CONFIRMVendor Advisory |
Change history (0)
No recorded changes yet.