CyberSecBulletin
CVE-2022-29404NVD status: Modified

Apache HTTP Server: Allocation of Resources Without Limits or Throttling

Published Updated By the CyberSecBulletin desk

CVE-2022-29404 is a high-severity allocation of resources without limits or throttling vulnerability in Apache HTTP Server from Apache, 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 Apache HTTP Server versions: 2.4.53 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 6.55% chance of exploitation within 30 days, which is in the top 6.08% of all scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Apache HTTP Server you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on httpd.apache.org 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
ApacheApache HTTP Server2.4.53 and earlierNot stated
ApacheHTTP Server2.4.53 and earlierNot stated
Fedora ProjectFedora35; 36Not stated
NetAppClustered Data OntapNot specified in the recordNot 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.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighNVD
CVSS 2.05.0MediumNVD

Official description

In Apache HTTP Server 2.4.53 and earlier, a malicious request to a lua script that calls r:parsebody(0) may cause a denial of service due to no default limit on possible input size.

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

The underlying weakness: Allocation of Resources Without Limits or Throttling

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

How developers prevent this class of flaw

  • Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
  • Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Allocation of Resources Without Limits or Throttling vulnerabilities (CWE-770)

Timeline

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

References

Third-party and government advisories

Other vulnerabilities in Apache HTTP Server

All Apache HTTP Server vulnerabilities

Recent Allocation of Resources Without Limits or Throttling vulnerabilities

Spotted an error? Tell us.