CyberSecBulletin
CVE-2022-2053NVD status: Modified

Undertow: Uncontrolled Resource Consumption

CVE-2022-2053 is a high-severity uncontrolled resource consumption vulnerability in Undertow, 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. Affected Undertow versions: Fixed in Undertow 2.2.19.Final, Undertow 2.3.0.Alpha2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.09% chance of exploitation within 30 days, higher than 66% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Undertow you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on bugzilla.redhat.com for workarounds and exact fixed builds.
  3. 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
UndertowUndertowFixed in Undertow 2.2.19.Final, Undertow 2.3.0.Alpha2Not stated
Red HatIntegration Camel KNot specified in the recordNot stated
Red HatJboss Fuse7.0.0Not stated

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
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

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

Official description

When a POST request comes through AJP and the request exceeds the max-post-size limit (maxEntitySize), Undertow's AjpServerRequestConduit implementation closes a connection without sending any response to the client/proxy. This behavior results in that a front-end proxy marking the backend worker (application server) as an error state and not forward requests to the worker for a while. In mod_cluster, this continues until the next STATUS request (10 seconds intervals) from the application server updates the server state. So, in the worst case, it can result in "All workers are in error state" and mod_cluster responds "503 Service Unavailable" for a while (up to 10 seconds). In mod_proxy_balancer, it does not forward requests to the worker until the "retry" timeout passes. However, luckily, mod_proxy_balancer has "forcerecovery" setting (On by default; this parameter can force the immediate recovery of all workers without considering the retry parameter of the workers if all workers of a balancer are in error state.). So, unlike mod_cluster, mod_proxy_balancer does not result in responding "503 Service Unavailable". An attacker could use this behavior to send a malicious request and trigger server errors, resulting in DoS (denial of service). This flaw was fixed in Undertow 2.2.19.Final, Undertow 2.3.0.Alpha2.

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

The underlying weakness: Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

How developers prevent this class of flaw

  • Ensure that protocols have specific limits of scale placed on them.
  • Ensure that all failures in resource allocation place the system into a safe posture.

More Uncontrolled Resource Consumption vulnerabilities (CWE-400)

Timeline

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

References

Other vulnerabilities in Undertow

All Undertow vulnerabilities

Recent Uncontrolled Resource Consumption vulnerabilities

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