CVE-2026-0794 Overview
CVE-2026-0794 is a use-after-free vulnerability affecting ALGO 8180 IP Audio Alerter devices that enables remote code execution through specially crafted SIP (Session Initiation Protocol) calls. This critical flaw allows remote attackers to execute arbitrary code on vulnerable devices without requiring any authentication, making it particularly dangerous for exposed network infrastructure.
The vulnerability stems from improper memory handling during SIP call processing, where the device fails to validate the existence of an object before performing operations on it. This classic use-after-free condition can be exploited by attackers to achieve code execution in the context of the affected device.
Critical Impact
Unauthenticated remote attackers can execute arbitrary code on ALGO 8180 IP Audio Alerter devices by exploiting improper memory handling in SIP call processing, potentially compromising network audio infrastructure.
Affected Products
- ALGO 8180 IP Audio Alerter devices
- Devices with SIP functionality enabled
- Network-exposed ALGO audio alerter installations
Discovery Timeline
- 2026-01-23 - CVE CVE-2026-0794 published to NVD
- 2026-01-26 - Last updated in NVD database
Technical Details for CVE-2026-0794
Vulnerability Analysis
This vulnerability is classified as CWE-416 (Use After Free), a memory corruption vulnerability that occurs when a program continues to use a pointer after the memory it references has been freed. In the context of the ALGO 8180 IP Audio Alerter, the flaw manifests specifically within the SIP call handling functionality.
When processing SIP calls, the device allocates memory objects to manage call state and related data structures. The vulnerability arises because the implementation fails to properly validate that these objects still exist before performing subsequent operations. When an attacker sends carefully crafted SIP messages that trigger specific sequences of allocation and deallocation, they can cause the device to reference freed memory, leading to memory corruption and ultimately arbitrary code execution.
The network-accessible nature of SIP services combined with the lack of authentication requirements significantly increases the risk profile of this vulnerability. IoT and VoIP infrastructure devices like the ALGO 8180 are often deployed in sensitive environments including healthcare facilities, educational institutions, and industrial settings where audio alerting systems are critical.
Root Cause
The root cause of this vulnerability is the lack of proper object lifecycle management in the SIP call handling code. Specifically, the code fails to validate the existence of an object prior to performing operations on it after the memory has been freed. This results in a use-after-free condition where stale pointers can be dereferenced, allowing attackers to manipulate memory contents and hijack execution flow.
Attack Vector
The attack vector is network-based (AV:N) and requires no authentication (PR:N) or user interaction (UI:N). An attacker can remotely target the SIP service running on the ALGO 8180 device by sending malicious SIP packets designed to trigger the use-after-free condition. The exploitation involves:
- Establishing a connection to the target device's SIP service
- Sending crafted SIP messages that manipulate memory allocation patterns
- Triggering the use-after-free by causing the device to reference a freed object
- Achieving code execution in the context of the device
While the attack complexity is noted as high (AC:H), successful exploitation grants the attacker full control over the affected device. For detailed technical information, refer to the Zero Day Initiative Advisory ZDI-26-016.
Detection Methods for CVE-2026-0794
Indicators of Compromise
- Unexpected SIP traffic patterns or anomalous SIP message sequences targeting ALGO 8180 devices
- Device crashes, unexpected reboots, or service interruptions on the SIP functionality
- Unusual network connections originating from the ALGO 8180 device to unknown external hosts
- Memory corruption errors or abnormal behavior logged by the device
Detection Strategies
- Deploy network-based intrusion detection systems (IDS) with rules to identify malformed or suspicious SIP packets
- Monitor SIP traffic for unusual message sequences or protocol anomalies targeting audio alerter devices
- Implement deep packet inspection on SIP communications to detect exploitation attempts
- Use SentinelOne Singularity to detect anomalous behavior on network segments containing vulnerable devices
Monitoring Recommendations
- Enable verbose logging on ALGO 8180 devices if available to capture SIP transaction details
- Configure network monitoring to alert on unexpected outbound connections from IoT/VoIP devices
- Establish baseline network behavior for ALGO devices and alert on deviations
- Monitor for firmware integrity changes or unauthorized configuration modifications
How to Mitigate CVE-2026-0794
Immediate Actions Required
- Isolate ALGO 8180 devices from untrusted networks and limit SIP service exposure
- Implement network segmentation to restrict access to SIP services from authorized hosts only
- Deploy firewall rules to block external access to SIP ports (typically UDP/TCP 5060-5061) on affected devices
- Monitor for vendor security updates and apply patches when available
Patch Information
As of the last update on 2026-01-26, organizations should monitor the vendor and the Zero Day Initiative Advisory ZDI-26-016 for patch availability. Apply firmware updates from ALGO as soon as they are released to address this vulnerability.
Workarounds
- Restrict SIP service access to trusted IP addresses only using access control lists (ACLs)
- Place ALGO 8180 devices behind a SIP-aware firewall or session border controller (SBC)
- Disable SIP functionality if not required for operations until a patch is available
- Implement VPN or other secure tunneling for remote SIP access requirements
# Example firewall rule to restrict SIP access (iptables)
# Allow SIP only from trusted management network
iptables -A INPUT -p udp --dport 5060 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 5060 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p udp --dport 5060 -j DROP
iptables -A INPUT -p tcp --dport 5060 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
