HTTP/2 Rapid reset attack The HTTP/2 protocol allows clients to indicate to the server that a previous stream should be canceled by sending a RSTSTREAM frame. The protocol does not require the client and server to coordinate the cancellation in any way, the client may do it unilaterally. The client may also assume that the cancellation will take effect immediately when the server receives the RSTSTREAM frame, before any other data from that TCP connection is processed.
Abuse of this feature is called a Rapid Reset attack because it relies on the ability for an endpoint to send a RSTSTREAM frame immediately after sending a request frame, which makes the other endpoint start working and then rapidly resets the request. The request is canceled, but leaves the HTTP/2 connection open.
The HTTP/2 Rapid Reset attack built on this capability is simple: The client opens a large number of streams at once as in the standard HTTP/2 attack, but rather than waiting for a response to each request stream from the server or proxy, the client cancels each request immediately.
The ability to reset streams immediately allows each connection to have an indefinite number of requests in flight. By explicitly canceling the requests, the attacker never exceeds the limit on the number of concurrent open streams. The number of in-flight requests is no longer dependent on the round-trip time (RTT), but only on the available network bandwidth.
In a typical HTTP/2 server implementation, the server will still have to do significant amounts of work for canceled requests, such as allocating new stream data structures, parsing the query and doing header decompression, and mapping the URL to a resource. For reverse proxy implementations, the request may be proxied to the backend server before the RSTSTREAM frame is processed. The client on the other hand paid almost no costs for sending the requests. This creates an exploitable cost asymmetry between the server and the client.
Multiple software artifacts implementing HTTP/2 are affected. This advisory was originally ingested from the swift-nio-http2 repo advisory and their original conent follows.
swift-nio-http2 specific advisory swift-nio-http2 is vulnerable to a denial-of-service vulnerability in which a malicious client can create and then reset a large number of HTTP/2 streams in a short period of time. This causes swift-nio-http2 to commit to a large amount of expensive work which it then throws away, including creating entirely new Channels to serve the traffic. This can easily overwhelm an EventLoop and prevent it from making forward progress.
swift-nio-http2 1.28 contains a remediation for this issue that applies reset counter using a sliding window. This constrains the number of stream resets that may occur in a given window of time. Clients violating this limit will have their connections torn down. This allows clients to continue to cancel streams for legitimate reasons, while constraining malicious actors.
An authenticated SQL injection vulnerability exists in the BIG-IP Configuration utility which
may allow an authenticated attacker with network access to the Configuration utility through the BIG-IP management port and/or self IP addresses to execute arbitrary system commands.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated
In all BIG-IP 13.1.x versions, when an iRule containing the HTTP::collect command is configured on a virtual server, undisclosed requests can cause Traffic Management Microkernel (TMM) to terminate.
In BIG-IP versions 17.0.x before 17.0.0.1, 16.1.x before 16.1.3.1, 15.1.x before 15.1.6.1, 14.1.x before 14.1.5.1, and 13.1.x before 13.1.5.1, when a SIP profile is configured on a virtual server, undisclosed messages can cause an increase in memory resource utilization.
In BIG-IP versions 17.0.x before 17.0.0.1, 16.1.x before 16.1.3.2, 15.1.x before 15.1.7, 14.1.x before 14.1.5.2, and 13.1.x before 13.1.5.1, when a sideband iRule is configured on a virtual server, undisclosed traffic can cause an increase in memory resource utilization.
In versions 16.1.x before 16.1.3.1, 15.1.x before 15.1.6.1, 14.1.x before 14.1.5.1, and 13.1.x before 13.1.5.1, When the Advanced WAF / ASM module is provisioned, an authenticated remote code execution vulnerability exists in the BIG-IP iControl REST interface.
On BIG-IP 15.0.0-15.1.0.2, 14.1.0-14.1.2.3, 13.1.0-13.1.3.2, 12.1.0-12.1.5.1, and 11.5.2-11.6.5.1 and BIG-IQ 7.0.0, 6.0.0-6.1.0, and 5.2.0-5.4.0, in a High Availability (HA) network failover in Device Service Cluster (DSC), the failover service does not require a strong form of authentication and HA network failover traffic is not encrypted by Transport Layer Security (TLS).
On BIG-IP 15.0.0-15.0.1.2, 14.1.0-14.1.2.2, 13.1.0-13.1.3.2, 12.1.0-12.1.5, and 11.5.2-11.6.5.1 and BIG-IQ 7.0.0, 6.0.0-6.1.0, and 5.2.0-5.4.0, users with non-administrator roles (for example, Guest or Resource Administrator) with tmsh shell access can execute arbitrary commands with elevated privilege via a crafted tmsh command.
On BIG-IP 15.0.0-15.0.1, 14.1.0-14.1.2.2, 13.1.0-13.1.3.1, 12.1.0-12.1.5, and 11.5.2-11.6.5.1, undisclosed HTTP behavior may lead to a denial of service.
On F5 BIG-IP 13.1.0-13.1.0.3, 13.0.0, 12.1.0-12.1.3.1, 11.6.1-11.6.3.1, 11.5.1-11.5.5, or 11.2.1 and Enterprise Manager 3.1.1, when authenticated administrative users run commands in the Traffic Management User Interface (TMUI), also referred to as the BIG-IP Configuration utility, restrictions on allowed commands may not be enforced.
On F5 BIG-IP 13.1.0-13.1.0.5, malformed TCP packets sent to a self IP address or a FastL4 virtual server may cause an interruption of service. The control plane is not exposed to this issue. This issue impacts the data plane virtual servers and self IPs.
On F5 BIG-IP 13.1.0-13.1.0.3, 13.0.0, 12.1.0-12.1.3.3, 11.6.1-11.6.3.1, 11.5.1-11.5.5, or 11.2.1, a malformed TLS handshake causes TMM to crash leading to a disruption of service. This issue is only exposed on the data plane when Proxy SSL configuration is enabled. The control plane is not impacted by this issue.
On F5 BIG-IP 13.1.0-13.1.0.5, when Large Receive Offload (LRO) and SYN cookies are enabled (default settings), undisclosed traffic patterns may cause TMM to restart.
On F5 BIG-IP 13.1.0-13.1.0.5, maliciously crafted HTTP/2 request frames can lead to denial of service. There is data plane exposure for virtual servers when the HTTP2 profile is enabled. There is no control plane exposure to this issue.
On F5 BIG-IP 13.1.0-13.1.0.3 or 13.0.0, when authenticated administrative users execute commands in the Traffic Management User Interface (TMUI), also referred to as the BIG-IP Configuration utility, restrictions on allowed commands may not be enforced.
An integer overflow flaw was found in the way the Linux kernel's networking subsystem processed TCP Selective Acknowledgment (SACK) segments. While processing SACK segments, the Linux kernel's socket buffer (SKB) data structure becomes fragmented. Each fragment is about TCP maximum segment size (MSS) bytes. To efficiently process SACK blocks, the Linux kernel merges multiple fragmented SKBs into one, potentially overflowing the variable holding the number of segments. A remote attacker could use this flaw to crash the Linux kernel by sending a crafted sequence of SACK segments on a TCP connection with small value of TCP MSS, resulting in a denial of service (DoS).
An excessive resource consumption flaw was found in the way the Linux kernel's networking subsystem processed TCP segments. If the Maximum Segment Size (MSS) of a TCP connection was set to low values, such as 48 bytes, it can leave as little as 8 bytes for the user data, which significantly increases the Linux kernel's resource (CPU, Memory, and Bandwidth) utilization. A remote attacker could use this flaw to cause a denial of service (DoS) by repeatedly sending network traffic on a TCP connection with low TCP MSS.
In BIG-IP Versions 16.1.x before 16.1.2.2, 15.1.x before 15.1.6.1, 14.1.x before 14.1.5, and all versions of 13.1.x, when a BIG-IP LTM Client SSL profile is configured on a virtual server to perform client certificate authentication with session tickets enabled, undisclosed requests cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
On F5 BIG-IP 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5, 14.1.x versions prior to 14.1.4.6, and 13.1.x versions prior to 13.1.5, when a Real Time Streaming Protocol (RTSP) profile is configured on a virtual server, undisclosed traffic can cause an increase in Traffic Management Microkernel (TMM) resource utilization. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated
On F5 BIG-IP 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5.1, 14.1.x versions prior to 14.1.4.6, and 13.1.x versions prior to 13.1.5, on platforms with an ePVA and the pva.fwdaccel BigDB variable enabled, undisclosed requests to a virtual server with a FastL4 profile that has ePVA acceleration enabled can cause the Traffic Management Microkernel (TMM) process to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated
On F5 BIG-IP LTM, Advanced WAF, ASM, or APM 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5, 14.1.x versions prior to 14.1.4.6, and all versions of 13.1.x, 12.1.x, and 11.6.x, when a virtual server is configured with HTTP, TCP on one side (client/server), and DTLS on the other (server/client), undisclosed requests can cause the TMM process to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated
Under certain conditions, on F5 BIG-IP ASM 13.0.0-13.1.0.7, 12.1.0-12.1.3.5, 11.6.0-11.6.3.1, 11.5.1-11.5.6, or 11.2.1, when processing CSRF protections, the BIG-IP ASM bd process may restart and produce a core file.
On BIG-IP version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.3, 13.1.x before 13.1.4.1, and all versions of 12.1.x and 11.6.x, when GPRS Tunneling Protocol (GTP) iRules commands or a GTP profile is configured on a virtual server, undisclosed GTP messages can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
On BIG-IP Advanced WAF and BIG-IP ASM version 16.x before 16.1.0x, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.3, 13.1.x before 13.1.4.1, and all versions of 12.1.x, when a WebSocket profile is configured on a virtual server, undisclosed requests can cause bd to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
On BIG-IP version 16.x before 16.1.0, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.2, 13.1.x before 13.1.4.1, and all versions of 12.1.x and 11.6.x, when the Intel QuickAssist Technology (QAT) compression driver is used on affected BIG-IP hardware and BIG-IP Virtual Edition (VE) platforms, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
On BIG-IP version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3, 14.1.x before 14.1.4, 13.1.x before 13.1.4, and 12.1.x before 12.1.6, when an HTTP profile is configured on a virtual server, undisclosed requests can cause a significant increase in system resource utilization. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
On BIG-IP Advanced WAF and BIG-IP ASM version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.3, 13.1.x before 13.1.4.1, and all versions of 12.1.x, when a WebSocket profile is configured on a virtual server, undisclosed requests can cause bd to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
On version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3, 14.1.x before 14.1.2.8, and all versions of 13.1.x and 12.1.x, when IPSec is configured on a BIG-IP system, undisclosed requests from an authorized remote (IPSec) peer, which already has a negotiated Security Association, can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
On BIG-IP version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3.1, 14.1.x before 14.1.4.3, 13.1.x before 13.1.4.1, and all versions of 12.1.x, when an SCTP profile with multiple paths is configured on a virtual server, undisclosed requests can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
BIG-IP version 16.0.x before 16.0.1.2, 15.1.x before 15.1.3, 14.1.x before 14.1.4.2, 13.1.x before 13.1.4.1, and all versions of 12.1.x and 11.6.x and all versions of BIG-IQ 8.x, 7.x, and 6.x are vulnerable to cross-site request forgery (CSRF) attacks through iControl SOAP. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.