CVE-2022-26943
Low boottime entropy and limited re-seeding of the pool renders the authentication challenge vulnerable to two attacks.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.35%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.35% probability · 28th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-338
- Affected
- motorola/mtm5500 firmware · motorola/mtm5400 firmware
- Source
- cert@ncsc.nl
References
- https://tetraburst.com/Technical Description
- https://tetraburst.com/Technical Description
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.