GOT2000 Series GT21 model: Use of Insufficiently Random Values
CVE-2023-3373 is a critical-severity use of insufficiently random values vulnerability in GOT2000 Series GT21 model from Mitsubishi Electric, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected GOT2000 Series GT21 model versions: 01.49.000 and prior. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.02% chance of exploitation within 30 days, higher than 64% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Gt21 Firmware to 01.50.000 or a later version.
- Update Gs21 Firmware to 01.50.000 or a later version.
- Read the advisory on mitsubishielectric.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 |
|---|---|---|---|
| Mitsubishi Electric | GOT2000 Series GT21 model | 01.49.000 and prior | Not stated |
| Mitsubishi Electric | GOT SIMPLE Series GS21 model | 01.49.000 and prior | Not stated |
| Mitsubishi Electric | Gt21 Firmware | before 01.50.000 | 01.50.000 |
| Mitsubishi Electric | Gs21 Firmware | before 01.50.000 | 01.50.000 |
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
- NoneNo data is disclosed.
- 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:N/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.9 | Medium | CNA (yd.MitsubishiElectric.co.jp) |
| CVSS 3.1 | 9.1 | Critical | NVD |
Official description
Predictable Exact Value from Previous Values vulnerability in Mitsubishi Electric Corporation GOT2000 Series GT21 model versions 01.49.000 and prior and GOT SIMPLE Series GS21 model versions 01.49.000 and prior allows a remote unauthenticated attacker to hijack data connections (session hijacking) or prevent legitimate users from establishing data connections (to cause DoS condition) by guessing the listening port of the data connection on FTP server and connecting to it.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Insufficiently Random Values
The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.
How developers prevent this class of flaw
- Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds. In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts. Pseudo-random number generators can produce predictable numbers if the generator is known and the seed can be guessed. A 256-bit seed is a good starting point for producing a random enough number.
- Consider a PRNG that re-seeds itself as needed from high quality pseudo-random output sources, such as hardware devices.
- Use products or modules that conform to FIPS 140-2 to avoid obvious entropy problems. Consult FIPS 140-2 Annex C (Approved Random Number Generators).
More Use of Insufficiently Random Values vulnerabilities (CWE-330)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- jvn.jp/vu/JVNVU92167394/index.htmlThird Party Advisory
- cisa.gov/news-events/ics-advisories/icsa-23-215-01Third Party Advisory, US Government Resource
Other vulnerabilities in GOT2000 Series GT21 model
- 7.5 High severity
Recent Use of Insufficiently Random Values vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
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