CVE-2026-90823: Buffer Overflow
FatPipe MPVPN, WARP, and IPVPN appliances running the end-of-life firmware version 10.1.2r60p100 contain a stack-based buffer overflow in /usr/sbin/authuserpass. An unauthenticated remote attacker with access to the affected management interface can submit a crafted authentication request that reaches an unchecked copy into a fixed-size stack buffer, potentially allowing arbitrary code execution as root.
The affected management interface is disabled by default and must be affirmatively enabled by the customer before the endpoint becomes reachable. FatPipe recommends restricting management access to trusted administrative networks and using WAN access control lists to limit access to trusted sources.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
If not required, leave the affected management interface disabled. (It is disabled by default and must be affirmatively enabled by the customer before the endpoint becomes reachable.)
FatPipe management interface enabled = false - Compensating control
Restrict management access to trusted administrative networks; do not expose the management interface directly to the public Internet.
- Compensating control
Use WAN access control lists (WAN ACLs) to permit connections only from authorized source addresses to the management interface.
- Operational
For FatPipe MPVPN, WARP, and IPVPN appliances running end-of-life firmware version 10.1.2r60p100, contact FatPipe Support to upgrade the appliances to the latest supported software release (remediated release is already available).
Event History
Frequently Asked Questions
Are appliances exposed in their default configuration?
No. The affected management interface is disabled by default. Exposure requires a customer to have affirmatively enabled that interface and made it reachable to an attacker.
What does an attacker need to exploit this issue?
An attacker needs network access to the affected management interface. No authentication or user interaction is required; a crafted authentication request can trigger the vulnerable unchecked stack copy.
What can be done if the affected firmware cannot be replaced immediately?
Restrict management access to trusted administrative networks and use WAN access control lists to allow only trusted source addresses. Disabling the management interface where it is not needed also removes the described reachable attack path.
How can I determine whether an appliance is affected?
Verify whether the appliance is an MPVPN, WARP, or IPVPN model running firmware version 10.1.2r60p100. Also determine whether its management interface has been enabled and is reachable from untrusted networks.