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CVE-2022-26923Microsoft Active Directory Domain Services Privilege Escalation Vulnerability

Patch nowHigh8.8Exploited, CISA due date 2022-09-08EPSS 84%, higher than 100% of scored CVEs

CVE-2022-26923 is a improper certificate validation in Microsoft Active Directory, rated high (8.8 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

TLS certificates are not checked properly, so an attacker on the path can pose as the server.

How it is reached

An attacker can exploit it over the network, with an ordinary user account, and nobody has to click anything.

What an attacker gains

A successful attack can read the data it protects, change data or behaviour and take it offline. In practice, this kind of flaw lets an attacker read or tamper with traffic, or pass a forged message as genuine.

Is it being exploited?

CISA added it to the Known Exploited Vulnerabilities catalog on 2022-08-18: it is being exploited in the wild. EPSS estimates a 84% 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: 2022-09-08.
  2. No fixed version is listed for Microsoft Active Directory itself; fixed versions for the other affected products are listed on this page.
  3. Until it is patched, review who holds accounts that can reach it.
  4. Check exposed instances for signs of compromise, not only for the version.

Description from NVD

Active Directory Domain Services Elevation of Privilege Vulnerability

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

  • Operating systems on servers, workstations or devices. Everything on the host inherits the flaw.
  • TLS termination and service-to-service channels. The flaw sits on the network path between clients and services.
  • Signature checks. The flaw sits on the network path between clients and services.

Trust boundaries in play

  • Authenticated network access. An account is needed, so exposure follows who can sign in: customers, partners or staff.
  • On the network path between clients and services. An attacker who crosses it can read or tamper with traffic, or pass a forged message as genuine.

Questions to answer about your own systems

  • Where does Microsoft Active Directory 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?

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.