QNAP VioStor NVR OS Command Injection
CVE-2023-47565 is a high-severity improper neutralization of special elements used in an OS command vulnerability in VioStor NVR from QNAP, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 5.0.0 as the first without the flaw, so updating VioStor NVR to that release or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on December 21, 2023, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update VioStor NVR to 5.0.0 or a later version.
- Update Qvr Firmware to 5.0.0 or a later version.
- CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- Read the advisory on qnap.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| QNAP | VioStor NVR | 4.x up to, but not including, 5.0.0 | 5.0.0 |
| QNAP | Qvr Firmware | 4.0.0 up to, but not including, 5.0.0 | 5.0.0 |
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
- LowA basic user account is enough.
- 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:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.0 | High | CNA (qnapsecurity.com.tw) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
An OS command injection vulnerability has been found to affect legacy QNAP VioStor NVR models running QVR Firmware 4.x. If exploited, the vulnerability could allow authenticated users to execute commands via a network. We have already fixed the vulnerability in the following versions: QVR Firmware 5.0.0 and later
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
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-47565US Government Resource
Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 7.2 High severity
- 8.8 High severity
- 7.2 High severity
- 8.8 High severity
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