CyberSecBulletin
CVE-2022-24796NVD status: Modified

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

CVE-2022-24796 is a critical-severity improper neutralization of special elements used in an OS command vulnerability in RaspberryMatic from Jens-maus, 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. Affected RaspberryMatic versions: >= 2.31.25.20180428, < 3.63.8.20220330. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 3.74% chance of exploitation within 30 days, which is in the top 9.97% of all scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of RaspberryMatic you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.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
Jens-mausRaspberryMatic>= 2.31.25.20180428, < 3.63.8.20220330Not 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
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 3.110.0CriticalCNA (github.com)
CVSS 3.19.8CriticalNVD
CVSS 2.010.0HighNVD

Official description

RaspberryMatic is a free and open-source operating system for running a cloud-free smart-home using the homematicIP / HomeMatic hardware line of IoT devices. A Remote Code Execution (RCE) vulnerability in the file upload facility of the WebUI interface of RaspberryMatic exists. Missing input validation/sanitization in the file upload mechanism allows remote, unauthenticated attackers with network access to the WebUI interface to achieve arbitrary operating system command execution via shell metacharacters in the HTTP query string. Injected commands are executed as root, thus leading to a full compromise of the underlying system and all its components. Versions after `2.31.25.20180428` and prior to `3.63.8.20220330` are affected. Users are advised to update to version `3.63.8.20220330` or newer. There are currently no known workarounds to mitigate the security impact and users are advised to update to the latest version available.

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

Other vulnerabilities in RaspberryMatic

All RaspberryMatic vulnerabilities

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

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