CVE-2026-57277: GeoWebPlayer Buffer Overflow Vulnerability

CVE-2026-57277 Overview

CVE-2026-57277 is a stack-based buffer overflow [CWE-120] in GeoVision GeoWebPlayer, an addon also known as "Web Plugin" in GV-VMS documentation and "WS Player" in VMS-Cloud. The component runs a local WebSocket server that extends GeoVision web interfaces such as GV-VMS and GV-Cloud. The connectionInfo command handler copies attacker-controlled JSON strings into fixed-size buffers using byte-by-byte loops without length checks. An attacker who tricks a user into visiting a malicious page can send crafted WebSocket messages to localhost and overflow the key field buffer, leading to memory corruption and potential code execution.

Critical Impact
Successful exploitation allows remote attackers to corrupt memory in the GeoWebPlayer process, enabling code execution in the user context after minimal user interaction.

Affected Products

GeoVision GeoWebPlayer (Web Plugin)
GeoVision GV-VMS with GeoWebPlayer addon
GeoVision GV-Cloud / VMS-Cloud WS Player

Discovery Timeline

2026-07-02 - CVE-2026-57277 published to NVD
2026-07-02 - Last updated in NVD database

Technical Details for CVE-2026-57277

Vulnerability Analysis

GeoWebPlayer exposes a WebSocket server that accepts JSON commands from localhost. The connectionInfo command is parsed by an internal routine referred to as handle_connection_info, which extracts fields required to connect to a camera. The handler copies several JSON string values, including the key field, into fixed-size stack buffers.

The copy operation uses manual byte-by-byte loops rather than bounded string functions. No length validation occurs before or during the copy. Supplying a key value longer than the destination buffer overflows adjacent stack memory, including saved return addresses and local variables.

Because the WebSocket listens on localhost, an attacker cannot reach it directly from the internet. However, a victim visiting a malicious web page in a browser can trigger a JavaScript WebSocket connection to the local port and deliver the crafted payload. This satisfies the User Interaction requirement while retaining a Network attack vector and a Changed scope, since the browser origin differs from the vulnerable process.

Root Cause

The root cause is missing bounds checking on attacker-supplied JSON fields in handle_connection_info. The function trusts the length of input strings and performs unchecked byte-by-byte copies into fixed-size buffers, a classic [CWE-120] buffer copy without size validation.

Attack Vector

An attacker hosts a malicious web page that opens a WebSocket to the local GeoWebPlayer port. The page sends a connectionInfo message with an oversized key field. The handler overflows a stack buffer inside the GeoWebPlayer process, allowing memory corruption and potential arbitrary code execution in the context of the logged-in user. Refer to the Talos Intelligence Vulnerability Report for the full technical write-up.

Detection Methods for CVE-2026-57277

Indicators of Compromise

Unexpected crashes or restarts of the GeoWebPlayer process on endpoints running GV-VMS, GV-Cloud, or VMS-Cloud.
WebSocket traffic from browser processes to the local GeoWebPlayer listening port containing oversized key values in connectionInfo payloads.
Child processes spawned by GeoWebPlayer that are inconsistent with normal camera streaming activity.

Detection Strategies

Inspect local WebSocket traffic for connectionInfo messages with JSON string fields exceeding expected lengths.
Monitor GeoWebPlayer for anomalous memory access violations, exception events, and Windows Error Reporting entries.
Correlate browser navigation events with GeoWebPlayer crashes to identify drive-by exploitation attempts.

Monitoring Recommendations

Log process creation and module load events for the GeoWebPlayer executable and alert on unexpected child processes.
Track outbound network activity from GeoWebPlayer, since post-exploitation typically involves command-and-control callbacks.
Enable crash dump collection on endpoints running GeoVision software to support forensic analysis of suspected exploitation.

How to Mitigate CVE-2026-57277

Immediate Actions Required

Consult the GeoVision Cyber Security Resource for the latest fixed versions of GeoWebPlayer and associated GV-VMS or GV-Cloud installers.
Uninstall or disable the GeoWebPlayer / Web Plugin addon on systems that do not require the browser-based camera interface.
Restrict which users can browse the internet from workstations that run GeoVision management software.

Patch Information

GeoVision publishes advisories and updated installers on its security page. Administrators should apply the vendor-provided patched build of GeoWebPlayer as referenced in the Talos Intelligence Vulnerability Report and the GeoVision Cyber Security Resource.

Workarounds

Block the local WebSocket port used by GeoWebPlayer with a host firewall rule when the plugin is not in active use.
Use browser policies or extensions to prevent untrusted sites from opening WebSocket connections to localhost.
Segment operator workstations from general-purpose browsing to reduce the chance of drive-by exploitation.

bash

# Example Windows Firewall rule to block loopback access to a GeoWebPlayer port
netsh advfirewall firewall add rule ^
  name="Block GeoWebPlayer WebSocket" ^
  dir=in ^
  action=block ^
  protocol=TCP ^
  localport=<GEOWEBPLAYER_PORT> ^
  interfacetype=loopback