CyberSecBulletin
CVE-2024-42330NVD status: Modified

Zabbix: Use of Externally-Controlled Format String

CVE-2024-42330 is a critical-severity use of externally-controlled format string vulnerability in Zabbix, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected Zabbix versions: 6.0.0 through 6.0.33; 6.4.0 through 6.4.18; 7.0.0 through 7.0.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.95% chance of exploitation within 30 days, higher than 62% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of Zabbix you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on support.zabbix.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
ZabbixZabbix6.0.0 through 6.0.33; 6.4.0 through 6.4.18; 7.0.0 through 7.0.3Not stated
Zabbixfrontend6.0.0 through 6.0.33; 6.4.0 through 6.4.18; 7.0.0 through 7.0.3Not 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
HighAdministrator-level access is required first.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
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:H/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (zabbix.com).

Official description

The HttpRequest object allows to get the HTTP headers from the server's response after sending the request. The problem is that the returned strings are created directly from the data returned by the server and are not correctly encoded for JavaScript. This allows to create internal strings that can be used to access hidden properties of objects.

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

The underlying weakness: Use of Externally-Controlled Format String

The product uses a function that accepts a format string as an argument, but the format string originates from an external source.

How developers prevent this class of flaw

  • Choose a language that is not subject to this flaw.
  • Ensure that all format string functions are passed a static string which cannot be controlled by the user, and that the proper number of arguments are always sent to that function as well. If at all possible, use functions that do not support the %n operator in format strings.
  • Run compilers and linkers with high warning levels, since they may detect incorrect usage.

More Use of Externally-Controlled Format String vulnerabilities (CWE-134)

Timeline

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

References

Other vulnerabilities in Zabbix

All Zabbix vulnerabilities

Recent Use of Externally-Controlled Format String vulnerabilities

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