CyberSecBulletin
CVE-2024-11187NVD status: Deferred

BIND 9: Asymmetric Resource Consumption (Amplification)

Published Updated By the CyberSecBulletin desk

CVE-2024-11187 is a high-severity asymmetric resource consumption (amplification) vulnerability in BIND 9 from ISC, 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 BIND 9 versions: 9.11.0 through 9.11.37; 9.16.0 through 9.16.50; 9.18.0 through 9.18.32, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 16.1% chance of exploitation within 30 days, which is in the top 3.02% of all scored CVEs.

Patch this week

EPSS places it among the vulnerabilities most likely to be exploited soon.

What to do

  1. Check which version of BIND 9 you run against the affected versions below, and install the vendor's latest release.
  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
ISCBIND 99.11.0 through 9.11.37; 9.16.0 through 9.16.50; 9.18.0 through 9.18.32; 9.20.0 through 9.20.4; 9.21.0 through 9.21.3; 9.11.3-S1 through 9.11.37-S1; 9.16.8-S1 through 9.16.50-S1; 9.18.11-S1 through 9.18.32-S1Not 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 CNA (isc.org).

Official description

It is possible to construct a zone such that some queries to it will generate responses containing numerous records in the Additional section. An attacker sending many such queries can cause either the authoritative server itself or an independent resolver to use disproportionate resources processing the queries. Zones will usually need to have been deliberately crafted to attack this exposure. This issue affects BIND 9 versions 9.11.0 through 9.11.37, 9.16.0 through 9.16.50, 9.18.0 through 9.18.32, 9.20.0 through 9.20.4, 9.21.0 through 9.21.3, 9.11.3-S1 through 9.11.37-S1, 9.16.8-S1 through 9.16.50-S1, and 9.18.11-S1 through 9.18.32-S1.

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

The underlying weakness: Asymmetric Resource Consumption (Amplification)

The product does not properly control situations in which an adversary can cause the product to consume or produce excessive resources without requiring the adversary to invest equivalent work or otherwise prove authorization, i.e., the adversary's influence is asymmetric.

How developers prevent this class of flaw

  • An application must make resources available to a client commensurate with the client's access level.
  • An application must, at all times, keep track of allocated resources and meter their usage appropriately.
  • Consider disabling resource-intensive algorithms on the server side, such as Diffie-Hellman key exchange.

More Asymmetric Resource Consumption (Amplification) vulnerabilities (CWE-405)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in BIND 9

All BIND 9 vulnerabilities

Recent Asymmetric Resource Consumption (Amplification) vulnerabilities

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