Upstream information
Description
In the Linux kernel, the following vulnerability has been resolved: tcp: do not accept ACK of bytes we never sent This patch is based on a detailed report and ideas from Yepeng Pan and Christian Rossow. ACK seq validation is currently following RFC 5961 5.2 guidelines: The ACK value is considered acceptable only if it is in the range of ((SND.UNA - MAX.SND.WND) <= SEG.ACK <= SND.NXT). All incoming segments whose ACK value doesn't satisfy the above condition MUST be discarded and an ACK sent back. It needs to be noted that RFC 793 on page 72 (fifth check) says: "If the ACK is a duplicate (SEG.ACK < SND.UNA), it can be ignored. If the ACK acknowledges something not yet sent (SEG.ACK > SND.NXT) then send an ACK, drop the segment, and return". The "ignored" above implies that the processing of the incoming data segment continues, which means the ACK value is treated as acceptable. This mitigation makes the ACK check more stringent since any ACK < SND.UNA wouldn't be accepted, instead only ACKs that are in the range ((SND.UNA - MAX.SND.WND) <= SEG.ACK <= SND.NXT) get through. This can be refined for new (and possibly spoofed) flows, by not accepting ACK for bytes that were never sent. This greatly improves TCP security at a little cost. I added a Fixes: tag to make sure this patch will reach stable trees, even if the 'blamed' patch was adhering to the RFC. tp->bytes_acked was added in linux-4.2 Following packetdrill test (courtesy of Yepeng Pan) shows the issue at hand: 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 1024) = 0 // ---------------- Handshake ------------------- // // when window scale is set to 14 the window size can be extended to // 65535 * (2^14) = 1073725440. Linux would accept an ACK packet // with ack number in (Server_ISN+1-1073725440. Server_ISN+1) // ,though this ack number acknowledges some data never // sent by the server. +0 < S 0:0(0) win 65535 <mss 1400,nop,wscale 14> +0 > S. 0:0(0) ack 1 <...> +0 < . 1:1(0) ack 1 win 65535 +0 accept(3, ..., ...) = 4 // For the established connection, we send an ACK packet, // the ack packet uses ack number 1 - 1073725300 + 2^32, // where 2^32 is used to wrap around. // Note: we used 1073725300 instead of 1073725440 to avoid possible // edge cases. // 1 - 1073725300 + 2^32 = 3221241997 // Oops, old kernels happily accept this packet. +0 < . 1:1001(1000) ack 3221241997 win 65535 // After the kernel fix the following will be replaced by a challenge ACK, // and prior malicious frame would be dropped. +0 > . 1:1(0) ack 1001SUSE information
Overall state of this security issue: Pending
This issue is currently rated as having important severity.
| SUSE | |
|---|---|
| Base Score | 7.5 |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:L |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Changed |
| Confidentiality Impact | None |
| Integrity Impact | High |
| Availability Impact | Low |
| CVSSv3 Version | 3.1 |
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 | Affected |
| SUSE Enterprise Storage 7.1 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP5 | kernel-default | Affected |
| SUSE Linux Enterprise Desktop 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP6 | kernel-default | Affected |
| SUSE Linux Enterprise Desktop 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 12 SP5 | kernel-default | Affected |
| SUSE Linux Enterprise High Performance Computing 12 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 12 SP5 | kernel-source-azure | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-default | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-source-azure | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | kernel-default | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | kernel-source-azure | Affected |
| SUSE Linux Enterprise Micro 5.1 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.1 | kernel-rt | Affected |
| SUSE Linux Enterprise Micro 5.1 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Micro 5.2 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.2 | kernel-rt | Affected |
| SUSE Linux Enterprise Micro 5.2 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-rt | Affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-rt | Affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Micro 5.5 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | kernel-default | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | kernel-default | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | kernel-default | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP6 | kernel-default | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Public Cloud 15 SP5 | kernel-source-azure | Affected |
| SUSE Linux Enterprise Module for Public Cloud 15 SP6 | kernel-source-azure | Affected |
| SUSE Linux Enterprise Real Time 12 SP5 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Real Time 15 SP5 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Real Time 15 SP6 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Server 12 SP5 | kernel-default | Affected |
| SUSE Linux Enterprise Server 12 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Server 12 SP5 | kernel-source-azure | Affected |
| SUSE Linux Enterprise Server 15 SP5 | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP5 | kernel-source-azure | Affected |
| SUSE Linux Enterprise Server 15 SP6 | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP6 | kernel-source-azure | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP5 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP5 | kernel-source-azure | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-source-azure | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-source-azure | Affected |
| SUSE Manager Proxy 4.3 | kernel-default | Affected |
| SUSE Manager Proxy 4.3 | kernel-source | Affected |
| SUSE Manager Retail Branch Server 4.3 | kernel-default | Affected |
| SUSE Manager Retail Branch Server 4.3 | kernel-source | Affected |
| SUSE Manager Server 4.3 | kernel-default | Affected |
| SUSE Manager Server 4.3 | kernel-source | Affected |
| SUSE Real Time Module 15 SP5 | kernel-source-rt | Affected |
| SUSE Real Time Module 15 SP6 | kernel-source-rt | Affected |
| openSUSE Leap 15.5 | kernel-default | Affected |
| openSUSE Leap 15.5 | kernel-source | Affected |
| openSUSE Leap 15.5 | kernel-source-azure | Affected |
| openSUSE Leap 15.5 | kernel-source-rt | Affected |
| openSUSE Leap 15.6 | kernel-default | Affected |
| openSUSE Leap 15.6 | kernel-source | Affected |
| openSUSE Leap 15.6 | kernel-source-azure | Affected |
| openSUSE Leap 15.6 | kernel-source-rt | Affected |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise Desktop 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-default | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-default | Affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-source | Affected |
| Products past their end of life and not receiving proactive updates anymore. | ||
| HPE Helion OpenStack 8 | kernel-source | Affected |
| SUSE CaaS Platform 4.0 | kernel-source | Affected |
| SUSE Enterprise Storage 6 | kernel-source | Affected |
| SUSE Enterprise Storage 7 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 12 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 12 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP1 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Micro 5.0 | kernel-default | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP1 | kernel-source | Affected |
| SUSE Linux Enterprise Real Time 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Real Time 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Real Time 15 SP3 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Server 11 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 11 SP4-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 12 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Server 12 SP3-BCL | kernel-source | Affected |
| SUSE Linux Enterprise Server 12 SP3-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise Server 12 SP3-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 12 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Server 12 SP4-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise Server 12 SP4-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 12 SP4-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP1 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | kernel-source | Affected |
| SUSE Linux Enterprise Server 15-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP4 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | kernel-source | Affected |
| SUSE Manager Proxy 4.0 | kernel-source | Affected |
| SUSE Manager Proxy 4.1 | kernel-source | Affected |
| SUSE Manager Proxy 4.2 | kernel-source | Affected |
| SUSE Manager Retail Branch Server 4.0 | kernel-source | Affected |
| SUSE Manager Retail Branch Server 4.1 | kernel-source | Affected |
| SUSE Manager Retail Branch Server 4.2 | kernel-source | Affected |
| SUSE Manager Server 4.0 | kernel-source | Affected |
| SUSE Manager Server 4.1 | kernel-source | Affected |
| SUSE Manager Server 4.2 | kernel-source | Affected |
| SUSE OpenStack Cloud 8 | kernel-source | Affected |
| SUSE OpenStack Cloud 9 | kernel-default | Affected |
| SUSE OpenStack Cloud 9 | kernel-source | Affected |
| SUSE OpenStack Cloud Crowbar 8 | kernel-source | Affected |
| SUSE OpenStack Cloud Crowbar 9 | kernel-default | Affected |
| SUSE OpenStack Cloud Crowbar 9 | kernel-source | Affected |
| SUSE Real Time Module 15 SP3 | kernel-source-rt | Affected |
| SUSE Real Time Module 15 SP4 | kernel-source-rt | Affected |
SUSE Timeline for this CVE
CVE page created: Wed May 29 14:00:22 2024CVE page last modified: Mon Jun 10 16:41:35 2024