Vulnerabilities

Proposed Generic UDP Encapsulation (GUE) (IETF Draft) do not validate or verify the source of a network packet allowing an attacker to spoof and route arbitrary traffic via an exposed network interface that can lead to spoofing, access control bypass, and other unexpected network behaviors. This can be considered similar to CVE-2020-10136.

GRE and GRE6 Protocols (RFC2784) do not validate or verify the source of a network packet allowing an attacker to spoof and route arbitrary traffic via an exposed network interface that can lead to spoofing, access control bypass, and other unexpected network behaviors. This can be considered similar to CVE-2020-10136.

IPv4-in-IPv6 and IPv6-in-IPv6 tunneling (RFC 2473) do not require the validation or verification of the source of a network packet, allowing an attacker to spoof and route arbitrary traffic via an exposed network interface. This is a similar issue to CVE-2020-10136.

CVE-2023-44487 is a flaw in the HTTP/2 protocol's stream handling (CWE-400, uncontrolled resource consumption) in which a client opens a large number of streams and immediately cancels them with RST_STREAM frames, forcing the server to repeatedly allocate and tear down per-stream state. When this 'rapid reset' pattern is driven at high volume from many sources, it exhausts server CPU and memory, producing a distributed denial-of-service; Google, Cloudflare and AWS all reported record-scale attacks using this technique. The only impact is availability (denial of service), not code execution or data exposure, but any system speaking HTTP/2 is in scope, including web servers, load balancers, API gateways and CDN edges, and client-side implementations are also affected in a reverse-direction variant. Because the weakness is in the protocol specification itself (attributed to IETF HTTP/2), virtually every deployment with HTTP/2 enabled is affected until vendors ship mitigations or patches. Exploitation is confirmed in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2023-10-10, and EPSS assigns a 100% probability of exploitation within 30 days.

Do: Apply mitigations per vendor instructions as required by CISA KEV/BOD 22-01 guidance — most major web server, load balancer, and CDN vendors have shipped patches or tuning knobs, so check and update each HTTP/2-facing component in your estate. Where patching is not yet possible, limit the number of concurrent HTTP/2 streams per connection, rate-limit new stream creation and inbound HTTP/2 connections, or disable HTTP/2 on internet-exposed servers. Confirm with your CDN or cloud provider that rapid-reset DDoS mitigations are in place at the edge.

CVE-2023-29552 is a protocol-level flaw in the IETF Service Location Protocol (SLP, RFC 2608) that permits an unauthenticated, remote attacker to register arbitrary services using spoofed UDP traffic sent to port 427. Any system running an SLP agent reachable on UDP 427 on an untrusted network can be abused as a reflector/amplifier, with reported amplification factors as high as roughly 2,200x, enabling large denial-of-service floods against third-party victims. The impact is availability only (CVSS 3.1: 7.5, A:H), and the attacker needs no privileges or user interaction. Affected parties include organizations running VMware ESXi, SUSE Linux Enterprise Server, or NetApp products (SMI-S Provider, Manager Server), as well as any host running the open-source Service Location Protocol implementation, since SLP is commonly enabled by default. The flaw was added to the CISA Known Exploited Vulnerabilities catalog on 2023-11-08 and is under active exploitation, with a high EPSS of 65.9% (99th percentile).

Do: Per the CISA required action, disable the SLP service (slpd) where it is not needed, or restrict UDP port 427 to trusted management networks and never expose it to the internet. Apply the mitigations or patches issued in the VMware, SUSE, and NetApp advisories, and inventory all hosts listening on 427/UDP, prioritizing internet-facing and untrusted-network systems since the flaw is under active exploitation.

Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers.

Bleichenbacher's attack on PKCS #1 v1.5 padding for RSA in STM32 cryptographic firmware library software expansion for STM32Cube (UM1924). The vulnerability can allow one to use Bleichenbacher's oracle attack to decrypt an encrypted ciphertext by making successive queries to the server using the vulnerable library, resulting in remote information disclosure.

Bleichenbacher's attack on PKCS #1 v1.5 padding for RSA in Microchip Libraries for Applications 2018-11-26 All up to 2018-11-26. The vulnerability can allow one to use Bleichenbacher's oracle attack to decrypt an encrypted ciphertext by making successive queries to the server using the vulnerable library, resulting in remote information disclosure.

The Internet Key Exchange v1 main mode is vulnerable to offline dictionary or brute force attacks. Reusing a key pair across different versions and modes of IKE could lead to cross-protocol authentication bypasses. It is well known, that the aggressive mode of IKEv1 PSK is vulnerable to offline dictionary or brute force attacks. For the main mode, however, only an online attack against PSK authentication was thought to be feasible. This vulnerability could allow an attacker to recover a weak Pre-Shared Key or enable the impersonation of a victim host or network.

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.