卡巴斯基互联网安全软件拦截AJAX请求致网站异常的技术问询

Hey there, let's break down why Kaspersky might be blocking your AJAX requests and throwing that TypeError: ns.GetCommandSrc is not a function error. I’ve dealt with similar security software interference issues before, so here’s what I think is going on and how to fix it:

• Web Threat Protection False Positive: Kaspersky’s real-time web scanner flags requests based on threat signatures, and sometimes legitimate API calls get caught in the crossfire. If your AJAX request to api.mysite.example has parameters, headers, or payload patterns that match its suspicious signature database (even incorrectly), it might intercept and modify the request/response—breaking the ns.GetCommandSrc function your site depends on.
• Script Injection Conflict: Kaspersky often injects its own protective scripts into web pages. If this injected code clashes with your site’s ns JavaScript namespace, it could overwrite or corrupt the GetCommandSrc method directly, leading to that type error.
• Strict Cross-Domain Rules (Despite CORS): Even with your Access-Control-Allow-Origin header configured, Kaspersky might have internal restrictions on cross-site requests. Non-standard headers, less common request methods, or even the specific structure of your API call could trigger its block rules.

• Add Your Domains to Kaspersky's Trusted List:
  1. Open Kaspersky Internet Security
  2. Navigate to Settings > Web Threat Protection > Trusted Sites
  3. Add both www.mysite.example and api.mysite.example to the list, enabling the "Do not scan traffic" option for each.
  4. Create a simple step-by-step guide for affected customers to follow this setup.
• Confirm Kaspersky is the Culprit:
  Ask a few affected users to temporarily disable Kaspersky’s web protection module. If the error disappears immediately, you’ve confirmed the security suite is the root cause.
• Inspect Modified Traffic:
  Use your browser’s DevTools (Network tab) to compare request/response data with Kaspersky active vs. inactive. Look for injected code, altered headers, or truncated payloads that could be breaking the ns namespace.
• Adjust Request Structure:
  If it’s a false positive, tweak minor parts of your AJAX request—like renaming a non-critical parameter, reordering headers, or adjusting the content-type (if feasible). Small changes can help avoid triggering Kaspersky’s signature detection.
• Submit a False Positive Report to Kaspersky:
  If none of the above works, send a report to Kaspersky’s support team including:
  • The exact error message: TypeError: ns.GetCommandSrc is not a function
  • Screenshots of the blocked request in DevTools
  • Details of your www.mysite.example and api.mysite.example endpoints
    They’ll review their signature database and can whitelist your requests if it’s confirmed as a false positive.

内容的提问来源于stack exchange，提问作者flecki89