Upstream information
Description
An issue was discovered in the IPv6 protocol specification, related to ICMP Packet Too Big (PTB) messages. (The scope of this CVE is all affected IPv6 implementations from all vendors.) The security implications of IP fragmentation have been discussed at length in [RFC6274] and [RFC7739]. An attacker can leverage the generation of IPv6 atomic fragments to trigger the use of fragmentation in an arbitrary IPv6 flow (in scenarios in which actual fragmentation of packets is not needed) and can subsequently perform any type of fragmentation-based attack against legacy IPv6 nodes that do not implement [RFC6946]. That is, employing fragmentation where not actually needed allows for fragmentation-based attack vectors to be employed, unnecessarily. We note that, unfortunately, even nodes that already implement [RFC6946] can be subject to DoS attacks as a result of the generation of IPv6 atomic fragments. Let us assume that Host A is communicating with Host B and that, as a result of the widespread dropping of IPv6 packets that contain extension headers (including fragmentation) [RFC7872], some intermediate node filters fragments between Host B and Host A. If an attacker sends a forged ICMPv6 PTB error message to Host B, reporting an MTU smaller than 1280, this will trigger the generation of IPv6 atomic fragments from that moment on (as required by [RFC2460]). When Host B starts sending IPv6 atomic fragments (in response to the received ICMPv6 PTB error message), these packets will be dropped, since we previously noted that IPv6 packets with extension headers were being dropped between Host B and Host A. Thus, this situation will result in a DoS scenario. Another possible scenario is that in which two BGP peers are employing IPv6 transport and they implement Access Control Lists (ACLs) to drop IPv6 fragments (to avoid control-plane attacks). If the aforementioned BGP peers drop IPv6 fragments but still honor received ICMPv6 PTB error messages, an attacker could easily attack the corresponding peering session by simply sending an ICMPv6 PTB message with a reported MTU smaller than 1280 bytes. Once the attack packet has been sent, the aforementioned routers will themselves be the ones dropping their own traffic.SUSE information
Overall state of this security issue: Ignore
This issue is currently rated as having low severity.
| National Vulnerability Database | SUSE | |
|---|---|---|
| Base Score | 5 | 2.6 |
| Vector | AV:N/AC:L/Au:N/C:N/I:N/A:P | AV:N/AC:H/Au:N/C:N/I:N/A:P |
| Access Vector | Network | Network |
| Access Complexity | Low | High |
| Authentication | None | None |
| Confidentiality Impact | None | None |
| Integrity Impact | None | None |
| Availability Impact | Partial | Partial |
| National Vulnerability Database | |
|---|---|
| Base Score | 8.6 |
| Vector | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| Attack Vector | Network |
| Attack Complexity | Low |
| Privileges Required | None |
| User Interaction | None |
| Scope | Changed |
| Confidentiality Impact | None |
| Integrity Impact | None |
| Availability Impact | High |
| CVSSv3 Version | 3 |
Note from the SUSE Security Team
This CVE describes an "undesirable feature" of the IPv6 protocol specification RFC 2460. The vulnerability is described to affect all standard compliant implementations, which may include the SUSE and openSUSE kernels.
As with other protocol level level issues, the decision was taken to not address this issue with a security update at this time, as it would make the kernel IPv6 implementation non non-compliant.
Remediation options (checks, filter implementations) or compatible work-arounds in the IPv6 implementation of the Linux kernel may be considered for a future update. A revision of the IPv6 specification, as indicated as desired by RFC 8021, will likewise be considered for future versions.
SUSE Bugzilla entry: 1020078 [RESOLVED / WONTFIX] No SUSE Security Announcements cross referenced.Status of this issue by product and package
Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.
| Product(s) | Source package | State |
|---|---|---|
| Products under general support and receiving all security fixes. | ||
| SUSE Enterprise Storage 7.1 | kernel-default | Unsupported |
| SUSE Enterprise Storage 7.1 | kernel-source | Unsupported |
| SUSE Linux Enterprise Micro 5.1 | kernel-default | Analysis |
| SUSE Linux Enterprise Micro 5.2 | kernel-default | Analysis |
| SUSE Linux Enterprise Real Time 15 SP3 | kernel-source | Analysis |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise High Performance Computing 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | kernel-default | Unsupported |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | kernel-source | Unsupported |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | kernel-default | Unsupported |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | kernel-source | Unsupported |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | kernel-default | Unsupported |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | kernel-source | Unsupported |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | kernel-default | Unsupported |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | kernel-source | Unsupported |
| SUSE Linux Enterprise Server 15 SP3 | kernel-default | Unsupported |
| SUSE Linux Enterprise Server 15 SP3 | kernel-source | Unsupported |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | kernel-default | Unsupported |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | kernel-source | Unsupported |
| SUSE OpenStack Cloud 9 | kernel-source | Analysis |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE CaaS Platform 4.0 | kernel-source | Analysis |
| SUSE Enterprise Storage 6 | kernel-source | Analysis |
| SUSE Linux Enterprise Desktop 12 SP1 | kernel-default | Ignore |
| SUSE Linux Enterprise Desktop 12 SP1 | kernel-source | Ignore |
| SUSE Linux Enterprise Desktop 12 SP2 | kernel-default | Unsupported |
| SUSE Linux Enterprise Desktop 12 SP2 | kernel-source | Unsupported |
| SUSE Linux Enterprise Desktop 12 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise Desktop 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise Desktop 15 SP3 | kernel-default | Unsupported |
| SUSE Linux Enterprise Desktop 15 SP3 | kernel-source | Unsupported |
| SUSE Linux Enterprise Micro 5.0 | kernel-default | Analysis |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Development Tools 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 11 SP4 | kernel-source | Ignore |
| SUSE Linux Enterprise Server 11 SP4-LTSS | kernel-default | Ignore |
| SUSE Linux Enterprise Server 11 SP4-LTSS | kernel-source | Ignore |
| SUSE Linux Enterprise Server 12 SP1 | kernel-default | Ignore |
| SUSE Linux Enterprise Server 12 SP1 | kernel-source | Ignore |
| SUSE Linux Enterprise Server 12 SP1-LTSS | kernel-source | Ignore |
| SUSE Linux Enterprise Server 12 SP2 | kernel-default | Ignore |
| SUSE Linux Enterprise Server 12 SP2 | kernel-source | Ignore |
| SUSE Linux Enterprise Server 12 SP2-BCL | kernel-source | Affected |
| SUSE Linux Enterprise Server 12 SP2-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise Server 12 SP2-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 12 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 12 SP4-ESPOS | kernel-source | Analysis |
| SUSE Linux Enterprise Server 12 SP4-LTSS | kernel-default | Analysis |
| SUSE Linux Enterprise Server 12 SP4-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP1-BCL | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP3-BCL | kernel-source | Analysis |
| SUSE Linux Enterprise Server for Raspberry Pi 12 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP1 | kernel-source | Ignore |
| SUSE Linux Enterprise Server for SAP Applications 12 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP4 | kernel-source | Analysis |
| SUSE Manager Proxy 4.0 | kernel-source | Analysis |
| SUSE Manager Proxy 4.2 | kernel-default | Unsupported |
| SUSE Manager Proxy 4.2 | kernel-source | Unsupported |
| SUSE Manager Retail Branch Server 4.0 | kernel-source | Analysis |
| SUSE Manager Retail Branch Server 4.2 | kernel-default | Unsupported |
| SUSE Manager Retail Branch Server 4.2 | kernel-source | Unsupported |
| SUSE Manager Server 4.0 | kernel-source | Analysis |
| SUSE Manager Server 4.2 | kernel-default | Unsupported |
| SUSE Manager Server 4.2 | kernel-source | Unsupported |
| SUSE OpenStack Cloud 7 | kernel-source | Affected |
| SUSE OpenStack Cloud Crowbar 9 | kernel-source | Analysis |
SUSE Timeline for this CVE
CVE page created: Sat Jan 14 13:02:56 2017CVE page last modified: Mon Apr 15 14:02:21 2024