CVE-2026-12848 Overview
CVE-2026-12848 is a stack-based buffer overflow [CWE-121] affecting the GeoVision GV-I/O Box 4E, a smart embedded device with 4 inputs and 4 relay outputs controlled over Ethernet and RS-485. The flaw resides in the DVRSearch service, which listens for UDP messages on port 10001 by default. Any unauthenticated attacker on the network can send a crafted UDP packet that triggers an attacker-controlled stack overflow in the DNS field handling logic. The vulnerability carries a CVSS 3.1 score of 10.0 with a scope change, indicating impact beyond the vulnerable component.
Critical Impact
Unauthenticated remote attackers on the network can corrupt the DVRSearch service stack via a single UDP packet, enabling arbitrary code execution on the embedded device.
Affected Products
- GeoVision GV-I/O Box 4E embedded controller
- DVRSearch service listening on UDP port 10001
- Devices exposing Ethernet management interfaces to untrusted networks
Discovery Timeline
- 2026-06-24 - CVE-2026-12848 published to NVD
- 2026-06-25 - Last updated in NVD database
Technical Details for CVE-2026-12848
Vulnerability Analysis
The DVRSearch service runs by default on the GV-I/O Box 4E and accepts UDP datagrams on port 10001. Upon receiving a message, the server reads up to 1460 bytes into a local buffer and stores a pointer to that buffer in a global variable. The service then constructs a reply buffer that incorporates network configuration values, including the configured DNS address.
The vulnerable code path performs strlen on g_network_config->dns_addr and copies the resulting bytes into a fixed offset (&reply_buf[248]) using memcpy. Because the DNS address content is influenced by attacker-supplied protocol input and no destination size check is enforced, the copy overflows the fixed-size stack buffer.
Root Cause
The root cause is missing bounds validation on a length value used in a memcpy operation into a stack-resident reply buffer. The destination at reply_buf[248] has a finite size, but the code trusts the length returned by strlen(g_network_config->dns_addr). When attacker-influenced data drives that length beyond the remaining buffer capacity, adjacent stack memory, including the saved return address, is overwritten.
Attack Vector
Exploitation requires only network reachability to UDP port 10001. No authentication, user interaction, or prior foothold is needed. An attacker sends a single crafted UDP datagram to the DVRSearch service that causes the device to populate the DNS configuration with an oversized value, then triggers the reply path that performs the unbounded memcpy. Successful exploitation yields control over execution flow within the service process running on the embedded device. See the Talos Intelligence Vulnerability Report for additional technical details.
Detection Methods for CVE-2026-12848
Indicators of Compromise
- Unsolicited UDP traffic to port 10001 originating from unexpected internal or external sources
- DVRSearch service crashes, restarts, or watchdog-triggered reboots on GV-I/O Box 4E devices
- Anomalous outbound connections from the embedded device to attacker-controlled infrastructure following UDP probes
Detection Strategies
- Inspect network flow records for UDP packets to port 10001 with payloads approaching the 1460-byte read limit
- Deploy IDS signatures that flag malformed DVRSearch protocol messages with oversized DNS or configuration fields
- Correlate device availability telemetry with UDP scanning activity targeting GeoVision IoT ranges
Monitoring Recommendations
- Log all ingress and egress traffic to and from GV-I/O Box 4E management interfaces
- Alert on first-seen source addresses sending traffic to UDP/10001 on the operational technology segment
- Forward device syslog and crash data to a centralized data lake for retrospective analysis against known exploitation patterns
How to Mitigate CVE-2026-12848
Immediate Actions Required
- Restrict UDP port 10001 access to a small set of management hosts using network ACLs or firewall rules
- Place GV-I/O Box 4E devices on a segmented VLAN isolated from general user and internet traffic
- Inventory all GeoVision GV-I/O Box 4E units and verify firmware versions against vendor advisories
- Monitor GeoVision Cybersecurity Resources for firmware updates addressing this CVE
Patch Information
No vendor patch is referenced in the NVD record at publication time. Administrators should consult the Talos Intelligence Vulnerability Report and the GeoVision Cybersecurity Resources page for updated firmware availability and apply fixed releases as soon as they are published.
Workarounds
- Block inbound UDP/10001 at perimeter and internal segmentation firewalls where DVRSearch discovery is not required
- Disable the DVRSearch service on devices where vendor configuration permits, falling back to static discovery
- Require VPN or jump-host access for any administrative interaction with the device
- Rate-limit UDP traffic to the operational technology segment to constrain mass scanning and exploitation attempts
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
