CyberSecBulletin
CVE-2024-21878NVD status: Analyzed

Envoy: Improper Neutralization of Special Elements used in an OS Command

CVE-2024-21878 is a critical-severity improper neutralization of special elements used in an OS command vulnerability in Envoy from Enphase, 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 8.2.4225 as the first without the flaw, so updating Envoy to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.44% chance of exploitation within 30 days, higher than 74% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Envoy to 8.2.4225 or a later version.
  2. Update Iq Gateway Firmware to 8.2.4225 or a later version.
  3. Read the advisory on enphase.com for workarounds and exact fixed builds.
  4. 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
EnphaseEnvoy8.x up to, but not including, 8.2.4225; 7.x; 6.x; 5.x; 4.x; 4.0 up to, but not including, 8.2.42258.2.4225
EnphaseIq Gateway Firmware4.0 up to, but not including, 8.2.42258.2.4225

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 4.09.2CriticalCNA (divd.nl)
CVSS 3.19.8CriticalNVD

Official description

Improper Neutralization of Special Elements used in a Command ('Command Injection') vulnerability in Enphase IQ Gateway (formerly known as Envoy) allows OS Command Injection. This vulnerability is present in an internal script.This issue affects Envoy: from 4.x up to and including 8.x and is currently unpatched.

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

The underlying weakness: Improper Neutralization of Special Elements used in an OS Command

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.

How developers prevent this class of flaw

  • If at all possible, use library calls rather than external processes to recreate the desired functionality.
  • For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in Envoy

All Envoy vulnerabilities

Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities

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