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

F5 BIG-IP Configuration utility contains an authentication bypass using an alternate path or channel vulnerability due to undisclosed requests that may allow an unauthenticated attacker with network access to the BIG-IP system through the management port and/or self IP addresses to execute system commands. This vulnerability can be used in conjunction with CVE-2023-46748.

On specific hardware platforms, on BIG-IP versions 16.1.x before 16.1.3.1, 15.1.x before 15.1.7, 14.1.x before 14.1.5.1, and all versions of 13.1.x, while Intel QAT (QuickAssist Technology) and the AES-GCM/CCM cipher is in use, undisclosed conditions can cause BIG-IP to send data unencrypted even with an SSL Profile applied.

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 16.1.3.1, 15.1.x before 15.1.7, 14.1.x before 14.1.5.1, and all versions of 13.1.x, and BIG-IQ all versions of 8.x and 7.x, an authenticated iControl REST user can cause an increase in memory resource utilization, via undisclosed requests.

In BIG-IP versions 16.1.x before 16.1.3, 15.1.x before 15.1.6.1, 14.1.x before 14.1.5, and all versions of 13.1.x, and BIG-IQ versions 8.x before 8.2.0.1 and all versions of 7.x, when an SSL key is imported on a BIG-IP or BIG-IQ system, undisclosed input can cause MCPD to terminate.

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.

F5 BIG-IP contains a missing authentication in critical function vulnerability which can allow for remote code execution, creation or deletion of files, or disabling services.

On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x before 14.1.4, 13.1.x before 13.1.3.6, and 12.1.x before 12.1.5.3, undisclosed requests to a virtual server may be incorrectly handled by the Traffic Management Microkernel (TMM) URI normalization, which may trigger a buffer overflow, resulting in a DoS attack. In certain situations, it may theoretically allow bypass of URL based access control or remote code execution (RCE). Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.

On BIG-IP versions 16.0.x before 16.0.1.1, 15.1.x before 15.1.2.1, 14.1.x before 14.1.4, 13.1.x before 13.1.3.6, and 12.1.x before 12.1.5.3 amd BIG-IQ 7.1.0.x before 7.1.0.3 and 7.0.0.x before 7.0.0.2, the iControl REST interface has an unauthenticated remote command execution vulnerability. Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.

In BIG-IP versions 15.0.0-15.1.0.3, 14.1.0-14.1.2.5, 13.1.0-13.1.3.3, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.1, the Traffic Management User Interface (TMUI), also referred to as the Configuration utility, has a Remote Code Execution (RCE) vulnerability in undisclosed pages.

On BIG-IP 15.1.0-15.1.0.1, 15.0.0-15.0.1.1, and 14.1.0-14.1.2.2, under certain conditions, TMM may crash or stop processing new traffic with the DPDK/ENA driver on AWS systems while sending traffic. This issue does not affect any other platforms, hardware or virtual, or any other cloud provider since the affected driver is specific to AWS.

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 BIG-IP 15.0.0-15.0.1.1 and 14.1.0-14.1.2.2, while processing specifically crafted traffic using the default 'xnet' driver, Virtual Edition instances hosted in Amazon Web Services (AWS) may experience a TMM restart.

On BIG-IP 15.0.0-15.0.1.1, 14.1.0-14.1.2.2, 14.0.0-14.0.1, 13.1.0-13.1.3.1, 12.1.0-12.1.5, and 11.6.0-11.6.5.1, the tmm crashes under certain circumstances when using the connector profile if a specific sequence of connections are made.

A use after free issue was found in the way Linux kernel's KVM hypervisor implements its device control API. While creating a device via kvmioctlcreatedevice(), device holds a reference to a VM object, latter this reference is transferred to caller's file descriptor table. If such file descriptor was to be closed, reference count to the VM object could become zero, potentially leading to use-after-free issue latter.

A user/process could use this flaw to crash the guest VM resulting in DoS issue OR potentially gain privileged access to a system.

Upstream patch: --------------- -> https://git.kernel.org/linus/cfa39381173d5f969daf43582c95ad679189cbc9

Reference: ---------- -> https://www.openwall.com/lists/oss-security/2019/02/18/2

A flaw named FragmentSmack was found in the way the Linux kernel handled reassembly of fragmented IPv4 and IPv6 packets. A remote attacker could use this flaw to trigger time and calculation expensive fragment reassembly algorithms by sending specially crafted packets which could lead to a CPU saturation and hence a denial of service on the system.

External References:

https://access.redhat.com/articles/3553061

https://www.kb.cert.org/vuls/id/641765

A fix is a merge commit in the Linux kernel tree:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c30f1fc041b74ecdb072dd44f858750414b8b19f

consisting of the following commits:

7969e5c40dfd04799d4341f1b7cd266b6e47f227 385114dec8a49b5e5945e77ba7de6356106713f4 fa0f527358bd900ef92f925878ed6bfbd51305cc

A flaw was found in the Linux kernels with commit b6a2fea39318 ("mm: variable length argument support", from July 19, 2007) but without commit da029c11e6b1 ("exec:Limit arg stack to at most 75% of STKLIM", from July 7, 2017). An integer overflow in the Linux kernel's createelftables() function. A local attacker can exploit this vulnerability via a SUID-root binary and obtain full root privileges.

Referenced commits: b6a2fea39318 ("mm: variable length argument support", from July 19, 2007) https://github.com/torvalds/linux/commit/b6a2fea39318e43fee84fa7b0b90d68bed92d2ba

da029c11e6b1 ("exec: Limit arg stack to at most 75% of STKLIM", from July 7, 2017) https://github.com/torvalds/linux/commit/da029c11e6b12f321f36dac8771e833b65cec962

Additional references: https://www.qualys.com/2018/09/25/cve-2018-14634/mutagen-astronomy-integer-overflow-linux-createelftables-cve-2018-14634.txt

A flaw was found in computer hardware of the Intel microprocessors related to the instruction-side TLB (Translation Lookaside Buffer) that caches translations from guest (and host) virtual addresses into physical addresses.

This is a software fix that attempts to prevent exploitation of the hardware through preventing a hacker from creating an exploitable condition

Additional information:

https://access.redhat.com/security/vulnerabilities/ifu-page-mce

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).

A Prototype Pollution vulnerability was found in lodash. Calling certain methods with untrusted JSON could lead to modifying objects up the prototype chain, including the global Object. A crafted JSON object passed to a vulnerable method could lead to denial of service or data injection, with various consequences.

When TCP Verified Accept is enabled on a TCP profile that is configured on a Virtual Server, undisclosed requests can cause an increase in memory resource utilization.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated

In BIG-IP versions 17.0.x before 17.0.0.1, 16.1.x before 16.1.3.1, 15.1.x before 15.1.7, and 14.1.x before 14.1.5.1, when an LTM TCP profile with Auto Receive Window Enabled is configured on a virtual server, undisclosed traffic can cause the virtual server to stop processing new client connections.

On all versions of 16.1.x, 15.1.x, 14.1.x, 13.1.x, 12.1.x, and 11.6.x of F5 BIG-IP, and F5 BIG-IP Guided Configuration (GC) all versions prior to 9.0, a stored cross-site scripting (XSS) vulnerability exists in an undisclosed page of the BIG-IP Configuration utility that allows an attacker to execute JavaScript in the context of the currently logged-in user. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated

In all versions,

BIG-IP and BIG-IQ 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.

In all versions of BIG-IP, when running in Appliance mode, an authenticated user assigned the Administrator role may be able to bypass Appliance mode restrictions, utilizing an undisclosed iControl REST endpoint. A successful exploit can allow the attacker to cross a security boundary.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

The BIG-IP and BIG-IQ systems do not encrypt some sensitive information written to Database (DB) variables.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.