CyberSecBulletin
CVE-2025-34271NVD status: Analyzed

Log Server: Cleartext Transmission of Sensitive Information

Published Updated By the CyberSecBulletin desk

CVE-2025-34271 is a critical-severity cleartext transmission of sensitive information vulnerability in Log Server from Nagios, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 2024R2.0.2 as the first without the flaw, so updating Log Server to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.74% chance of exploitation within 30 days, higher than 55% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Log Server to 2024R2.0.2 or a later version.
  2. Read the advisory on nagios.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
NagiosLog Serverbefore 2024R2.0.22024R2.0.2

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
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:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.08.7HighCNA (vulncheck.com)
CVSS 3.19.8CriticalNVD

Official description

Nagios Log Server versions prior to 2024R2.0.2 contain a vulnerability in the cluster manager component when requesting sensitive credentials from peer nodes over an unencrypted channel even when SSL/TLS is enabled in the product configuration. As a result, an attacker positioned on the network path can intercept credentials in transit. Captured credentials could allow the attacker to authenticate as a cluster node or service account, enabling further unauthorized access, lateral movement, or system compromise.

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

The underlying weakness: Cleartext Transmission of Sensitive Information

The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.

How developers prevent this class of flaw

  • Before transmitting, encrypt the data using reliable, confidentiality-protecting cryptographic protocols.
  • When using web applications with SSL, use SSL for the entire session from login to logout, not just for the initial login page.
  • When designing hardware platforms, ensure that approved encryption algorithms (such as those recommended by NIST) protect paths from security critical data to trusted user applications.

More Cleartext Transmission of Sensitive Information vulnerabilities (CWE-319)

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

Patches and release notes

Other vulnerabilities in Log Server

All Log Server vulnerabilities

Recent Cleartext Transmission of Sensitive Information vulnerabilities

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