CyberSecBulletin
CVE-2025-0306NVD status: Deferred

Red Hat Enterprise Linux 10: Covert Timing Channel

CVE-2025-0306 is a high-severity covert timing channel vulnerability in Red Hat Enterprise Linux 10 from Red Hat, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.66% chance of exploitation within 30 days, higher than 52% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Red Hat Enterprise Linux 10 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
Red HatRed Hat Enterprise Linux 10Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 6Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 7Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 8Not specified in the recordNot stated
Red HatRed Hat Enterprise Linux 9Not specified in the recordNot stated
Red HatRed Hat Storage 3Not 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
HighSuccess depends on conditions outside the attacker's control.
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
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (redhat.com).

Official description

A vulnerability was found in Ruby. The Ruby interpreter is vulnerable to the Marvin Attack. This attack allows the attacker to decrypt previously encrypted messages or forge signatures by exchanging a large number of messages with the vulnerable service.

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

The underlying weakness: Covert Timing Channel

Covert timing channels convey information by modulating some aspect of system behavior over time, so that the program receiving the information can observe system behavior and infer protected information.

How developers prevent this class of flaw

  • Whenever possible, specify implementation strategies that do not introduce time variances in operations.
  • Often one can artificially manipulate the time which operations take or -- when operations occur -- can remove information from the attacker.
  • It is reasonable to add artificial or random delays so that the amount of CPU time consumed is independent of the action being taken by the application.

More Covert Timing Channel vulnerabilities (CWE-385)

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 Red Hat Enterprise Linux 10

All Red Hat Enterprise Linux 10 vulnerabilities

Recent Covert Timing Channel vulnerabilities

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