dbcve.org
G42 FirmwareOperating system · Nokia

CVE-2025-27021

HIGH · 7.8 CVSS v3.1 Published 2025-07-02
Fix available
A fix is available. Upgrade to 7.1 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The misconfiguration in the sudoers configuration of the operating system in Infinera G42 version R6.1.3 allows low privileged OS users to read/write physical memory via devmem command line tool. This could allow sensitive information disclosure, denial of service, and privilege escalation by tampering with kernel memory. Details: The output of "sudo -l" reports the presence of "devmem" command executable as super user without using a password. This command allows to read and write an arbitrary memory area of the target device, specifying an absolute address.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A sudoers misconfiguration in Infinera G42 R6.1.3 permits low-privileged OS users to execute the devmem utility with root privileges without password authentication. The devmem command provides direct read/write access to physical memory addresses, enabling an attacker to read sensitive data, modify kernel memory, or escalate privileges to root.

MitigationRemove or restrict the devmem entry from the sudoers configuration to prevent unprivileged users from executing it with elevated permissions. Implement the principle of least privilege for sudo rules.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
G42 FirmwareOperating system
Affected:>= 6.1.3, < 7.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify firmware version
    Check the installed Nokia G42 firmware version using the device management interface, command line (e.g., 'version' or 'show system info'), or check /etc/version file if accessible via console.
    Affected if The firmware version is greater than or equal to 6.1.3 and less than 7.1.
  2. Locate sudoers configuration
    Inspect the sudoers configuration files. Look in /etc/sudoers and any files in /etc/sudoers.d/ directory. Use 'visudo' or 'sudo -l' to safely view the configuration.
    Affected if The sudoers configuration contains an entry granting ALL users (or a low-privileged user group) permission to run /sbin/devmem or /usr/bin/devmem with elevated privileges.
  3. Verify devmem sudoers entry details
    Search the sudoers configuration for 'devmem' using grep or by reviewing the full sudoers output. Check if the entry includes NOPASSWD: flag which allows execution without password authentication.
    Affected if A sudoers rule exists that permits devmem execution with root privileges AND includes the NOPASSWD: tag, allowing unprivileged users to run it without entering a password.
  4. Test devmem execution as non-root user
    As a low-privileged OS user (non-root), attempt to execute 'sudo devmem <address>' or 'sudo /sbin/devmem <address>'. Verify if password authentication is required or if the command executes directly.
    Affected if A non-root user can execute devmem with sudo without being prompted for a password, confirming the misconfiguration is exploitable.

If the Nokia G42 firmware version is 6.1.3 or higher but below 7.1, AND the sudoers configuration contains an unrestricted devmem entry allowing low-privileged users to run it with root privileges (especially with NOPASSWD), the environment is affected by this CVE.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 7.1 or later
Fixed in 7.1
Interim mitigation

Remove or restrict the devmem entry from the sudoers configuration to prevent unprivileged users from executing it with elevated permissions. Implement the principle of least privilege for sudo rules.

Recommended fix High confidence

G42 firmware version 7.1 or later

  1. 1. Schedule a maintenance window for the firmware upgrade
  2. 2. Back up the current device configuration according to Infinera's documentation
  3. 3. Obtain the Infinera G42 firmware version 7.1 or later from Infinera's official support portal
  4. 4. Upload the firmware image to the device using the vendor's recommended procedure
  5. 5. Verify the upgrade completed successfully and the device is operational
  6. 6. Confirm the fix by running 'sudo -l' as a low-privileged user and verifying 'devmem' no longer appears in the allowed commands list

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in G42 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-27021 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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