Skip to main content
veriom
Menu

Explore Veriom products, resources, and account pages.

CVE-2023-44487HTTP/2 Rapid Reset Attack Vulnerability

Patch nowHigh7.5Exploited, CISA due date 2023-10-31EPSS 100%, higher than 100% of scored CVEs

CVE-2023-44487 is a uncontrolled resource consumption in IETF HTTP/2, rated high (7.5 on CVSS 3.1).

Why this priority: Exploited in the wild: listed in CISA's KEV catalog.

Published · Updated · NVD status: Analyzed

What it is

Requests can consume unbounded CPU, memory or connections and starve the service.

How it is reached

An attacker can exploit it over the network, without an account, and nobody has to click anything.

What an attacker gains

A successful attack can take it offline. In practice, this kind of flaw lets an attacker exhaust CPU, memory or connections until the service stops answering.

Is it being exploited?

CISA added it to the Known Exploited Vulnerabilities catalog on 2023-10-10: it is being exploited in the wild. It can be exploited automatically, at scale. EPSS estimates a 100% chance of exploitation activity in the next 30 days, higher than 100% of scored CVEs.

What to do

  1. Treat it as urgent: it is on CISA's KEV list. CISA's deadline for US federal agencies: 2023-10-31.
  2. No fixed version is listed for IETF HTTP/2 itself; fixed versions for the other affected products are listed on this page.
  3. Until it is patched, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
  4. Check exposed instances for signs of compromise, not only for the version.

Description from NVD

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

What this means for your architecture.

A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.

Components it touches

  • Network edge devices: VPNs, firewalls, routers and gateways. They sit between the internet and internal networks, so a flaw in one is often the first step into everything behind it.
  • Operating systems on servers, workstations or devices. Everything on the host inherits the flaw.
  • Public entry points and shared services that must stay up. The flaw sits between untrusted traffic and shared capacity.

Trust boundaries in play

  • Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
  • Between untrusted traffic and shared capacity. An attacker who crosses it can exhaust CPU, memory or connections until the service stops answering.

Questions to answer about your own systems

  • Where does IETF HTTP/2 run in your systems, and at which version?
  • Which of those instances can be reached from the internet or partner networks?
  • What can it reach once compromised: which data stores, secrets and services?
See how Veriom maps an architectureTake the interactive tour

Read more

Sources

  • CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
  • Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
  • Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
  • Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.