Eternus Cs8000 Firmware: Improper Neutralization of Special Elements used in an OS Command
CVE-2022-31795 is a critical-severity improper neutralization of special elements used in an OS command vulnerability in Eternus Cs8000 Firmware from Fujitsu, 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 8.1 as the first without the flaw, so updating Eternus Cs8000 Firmware to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 3.16% chance of exploitation within 30 days, higher than 88% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Eternus Cs8000 Firmware to 8.1 or a later version.
- Read the advisory on support.ts.fujitsu.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Fujitsu | Eternus Cs8000 Firmware | before 8.1; 8.1 | 8.1 |
Version data comes from NVD's product matching. 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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 2.0 | 10.0 | High | NVD |
Official description
An issue was discovered on Fujitsu ETERNUS CentricStor CS8000 (Control Center) devices before 8.1A SP02 P04. The vulnerability resides in the grel_finfo function in grel.php. An attacker is able to influence the username (user), password (pw), and file-name (file) parameters and inject special characters such as semicolons, backticks, or command-substitution sequences in order to force the application to execute arbitrary commands.
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.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- cwe.mitre.org/data/definitions/78.htmlThird Party Advisory
Technical write-ups (may include proof of concept)
- research.nccgroup.com/2022/05/27/technical-advisory-fujitsu-centricstor-control-center-v8-1-unauthenticated-c…Exploit, Third Party Advisory
Other vulnerabilities in Eternus Cs8000 Firmware
- 9.8 Critical severity
Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 9.8 Critical severity
- 10.0 High severity
- 9.8 Critical severity
- 10.0 High severity
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