CyberSecBulletin
CVE-2024-38865NVD status: Analyzed

Checkmk: Improper Neutralization of Delimiters

CVE-2024-38865 is a high-severity improper neutralization of delimiters vulnerability in Checkmk, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 2.3.0p25, 2.2.0p39 as the first without the flaw, so updating Checkmk to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.88% chance of exploitation within 30 days, higher than 60% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Checkmk to 2.3.0p25 or 2.2.0p39, whichever matches your release line, or a later version.
  2. Read the advisory on checkmk.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
CheckmkCheckmk2.3.0 up to, but not including, 2.3.0p25; 2.2.0 up to, but not including, 2.2.0p39; 2.1.0 through 2.1.0p502.3.0p25, 2.2.0p39

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
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 4.06.0MediumCNA (checkmk.com)
CVSS 3.18.8HighNVD

Official description

Improper neutralization of livestatus command delimiters in a specific endpoint within RestAPI of Checkmk prior to 2.2.0p39, 2.3.0p25, and 2.1.0p51 (EOL) allows arbitrary livestatus command execution. Exploitation requires the attacker to have a contact group assigned to their user account and for an event to originate from a host with the same contact group or from an event generated with an unknown host.

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

The underlying weakness: Improper Neutralization of Delimiters

The product does not neutralize or incorrectly neutralizes delimiters.

How developers prevent this class of flaw

  • Developers should anticipate that delimiters will be injected/removed/manipulated in the input vectors of their product. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
  • While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments. The most conservative approach is to escape or filter all characters that do not pass an extremely strict allowlist (such as everything that is not alphanumeric or white space). If some special characters are still needed, such as white space, wrap each argument in quotes after the escaping/filtering step. Be careful of argument injection (CWE-88).
  • Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

More Improper Neutralization of Delimiters vulnerabilities (CWE-140)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Checkmk

All Checkmk vulnerabilities

Recent Improper Neutralization of Delimiters vulnerabilities

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