CyberSecBulletin
CVE-2022-22690NVD status: Modified

Umbraco CMS: Inconsistent Interpretation of HTTP Requests

Published Updated By the CyberSecBulletin desk

CVE-2022-22690 is a high-severity inconsistent interpretation of HTTP requests vulnerability in Umbraco CMS from Umbraco, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 9.2.0 as the first without the flaw, so updating Umbraco CMS to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.18% chance of exploitation within 30 days, higher than 68% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Umbraco CMS to 9.2.0 or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
UmbracoUmbraco CMSbefore 9.2.09.2.0

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.6HighCNA (appcheck-ng.com)
CVSS 3.17.5HighNVD
CVSS 2.05.0MediumNVD

Official description

Within the Umbraco CMS, a configuration element named "UmbracoApplicationUrl" (or just "ApplicationUrl") is used whenever application code needs to build a URL pointing back to the site. For example, when a user resets their password and the application builds a password reset URL or when the administrator invites users to the site. For Umbraco versions less than 9.2.0, if the Application URL is not specifically configured, the attacker can manipulate this value and store it persistently affecting all users for components where the "UmbracoApplicationUrl" is used. For example, the attacker is able to change the URL users receive when resetting their password so that it points to the attackers server, when the user follows this link the reset token can be intercepted by the attacker resulting in account takeover.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Inconsistent Interpretation of HTTP Requests

The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

How developers prevent this class of flaw

  • Use a web server that employs a strict HTTP parsing procedure, such as Apache.
  • Terminate the client session after each request.

More Inconsistent Interpretation of HTTP Requests vulnerabilities (CWE-444)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Umbraco CMS

All Umbraco CMS vulnerabilities

Recent Inconsistent Interpretation of HTTP Requests vulnerabilities

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