Mobile Radio: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
CVE-2022-26943 is a high-severity use of cryptographically weak pseudo-random number generator (PRNG) vulnerability in Mobile Radio from Motorola, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected Mobile Radio versions: MTM5000. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.36% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Mobile Radio you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Motorola | Mobile Radio | MTM5000 | Not stated |
| Motorola | mtm5000_series_firmware | all versions | Not stated |
| Motorola | Mtm5500 Firmware | Not specified in the record | Not stated |
| Motorola | Mtm5400 Firmware | Not specified in the record | Not 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
- AdjacentThe attacker must be on the same local network segment.
- 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:A/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 | 8.8 | High | CNA (ncsc.nl) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
The Motorola MTM5000 series firmwares generate TETRA authentication challenges using a PRNG using a tick count register as its sole entropy source. Low boottime entropy and limited re-seeding of the pool renders the authentication challenge vulnerable to two attacks. First, due to the limited boottime pool entropy, an adversary can derive the contents of the entropy pool by an exhaustive search of possible values, based on an observed authentication challenge. Second, an adversary can use knowledge of the entropy pool to predict authentication challenges. As such, the unit is vulnerable to CVE-2022-24400.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.
How developers prevent this class of flaw
- Use functions or hardware which use a hardware-based random number generation for all crypto. This is the recommended solution. Use CyptGenRandom on Windows, or hw_rand() on Linux.
More Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities (CWE-338)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
- tetraburst.com/Technical Description
Other vulnerabilities in Mobile Radio
- 8.2 High severity
- 8.2 High severity
- 8.8 High severity
Recent Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerabilities
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 8.8 High severity
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