Volt Typhoon used rotating Silent Train relays for zero-days
Lumen says exploited products included Versa, N-able, Cisco SD-WAN, VeloCloud and possibly Quest KACE; KeyDrift hit Cisco controllers.
OS Command Injection in N-able N-central Before 2025.3.1
CISA: N-able N-Central Command Injection Vulnerability
N-able N-central, an RMM platform widely used by managed service providers, contains an OS command injection flaw (CWE-78) caused by improper input validation (CWE-20), allowing an attacker to execute arbitrary operating-system commands on the N-central server. The flaw is reachable over the network (AV:N) and requires only low-privileged access with no user interaction, per the CVSS 4.0 vector. Successful exploitation yields high impact on confidentiality, integrity, and availability, and the 'subsequent system' impacts indicate compromise can extend beyond the N-central server itself, putting all endpoints that the affected MSP manages at risk. All N-central deployments running versions before 2025.3.1 are affected. The flaw is being exploited in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2025-08-13 following reported customer compromises, though no public proof-of-concept is known and ransomware use is unknown.
What to do: Upgrade N-central to version 2025.3.1 or later immediately, as the flaw is under active exploitation and CISA KEV requires federal agencies to apply vendor mitigations per BOD 22-01 or discontinue use. MSPs should check their N-central servers for signs of compromise, review accounts for anomalous or low-privileged sessions, and assume downstream managed endpoints may be at risk given the subsequent-system impact. Note that this is one of two recently patched N-central flaws being exploited in the wild, so ensure all recent hotfixes (multiple releases in recent weeks) are applied.
| Product | Affected |
|---|---|
| N-able N-central | all versions before 2025.3.1 |
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Improper Input Validation vulnerability in N-able N-central allows OS Command Injection.This issue affects N-central: before 2025.3.1.
Lumen says exploited products included Versa, N-able, Cisco SD-WAN, VeloCloud and possibly Quest KACE; KeyDrift hit Cisco controllers.
Black Lotus Labs says four confirmed zero-days hit VeloCloud, Cisco SD-WAN, N-central, and Versa Director.
Lumen says four confirmed zero-day campaigns hit management platforms, with credential theft and chains of compromised devices.
Lumen links the relay network to four confirmed zero-days and one likely flaw, with sessions rebuilt in under two minutes.
Black Lotus Labs says the rotating SOHO and IoT relay network hit hundreds of victims, including US critical infrastructure.
Volt Typhoon built Silent Train framework using zero-days in Quest KACE, N-central, Cisco SD-WAN and VeloCloud to access U.S. critical infrastructure.
N-able shipped Hotfix 4 for a CVSS 10.0 unauthenticated RCE (CVE-2026-86218) in N-central RMM, with conflicting statements on exploitation.
Today 221 readers · 228 views · 172 reads · all time 158K views