---
title: Internet Browsers Blocking Some Ports Due To Security Vulnerabilities
description: Internet Browsers Blocking Some Ports Due To Security Vulnerabilities
---

[Securafy Knowledge Hub](https://blog.securafy.com)

- [Topics](https://blog.securafy.com/#sf-cover)
- [Tools](https://blog.securafy.com/#sf-tools)
- [Books & Guides](https://blog.securafy.com/#sf-books)

[Talk to Securafy](https://meetings.hubspot.com/securafy/strategy-call)

[Topics](https://blog.securafy.com/#sf-cover) [Tools](https://blog.securafy.com/#sf-tools) [Books & Guides](https://blog.securafy.com/#sf-books) [Talk to Securafy](https://meetings.hubspot.com/securafy/strategy-call)

[Knowledge Hub](https://blog.securafy.com) / IT Operations

IT Operations

# Internet Browsers Blocking Some Ports Due To Security Vulnerabilities

Internet Browsers Blocking Some Ports Due To Security Vulnerabilities

![Randy Hall](https://blog.securafy.com/hubfs/Randy%20Hall%202.png) By Randy Hall Updated Jul 2024 2 min read Share [**](https://www.linkedin.com/sharing/share-offsite/?url=https://blog.securafy.com/2021/03/31/internet-browsers-blocking-some-ports-due-to-security-vulnerabilities) [**](https://twitter.com/intent/tweet?url=https://blog.securafy.com/2021/03/31/internet-browsers-blocking-some-ports-due-to-security-vulnerabilities&text=%3Cspan+id%3D%22hs_cos_wrapper_name%22+class%3D%22hs_cos_wrapper+hs_cos_wrapper_meta_field+hs_cos_wrapper_type_text%22+style%3D%22%22+data-hs-cos-general-type%3D%22meta_field%22+data-hs-cos-type%3D%22text%22+%3EInternet+Browsers+Blocking+Some+Ports+Due+To+Security+Vulnerabilities%3C%2Fspan%3E) [**](mailto:?subject=%3Cspan+id%3D%22hs_cos_wrapper_name%22+class%3D%22hs_cos_wrapper+hs_cos_wrapper_meta_field+hs_cos_wrapper_type_text%22+style%3D%22%22+data-hs-cos-general-type%3D%22meta_field%22+data-hs-cos-type%3D%22text%22+%3EInternet+Browsers+Blocking+Some+Ports+Due+To+Security+Vulnerabilities%3C%2Fspan%3E&body=https://blog.securafy.com/2021/03/31/internet-browsers-blocking-some-ports-due-to-security-vulnerabilities)

![](https://static.hsstatic.net/BlogImporterAssetsUI/ex/missing-image.png)If you rely on TCP port 554, you'll probably want to do a bit of reconfiguration.

Last year, security researchers discovered a new version of the NAT Slipstream vulnerability that allowed hackers to deploy malicious scripts in order to bypass a website visitor's NAT firewall and access any TCP/UDP port on the visitor's internal network.

If this issue sounds vaguely familiar, it's because this isn't the first time it has come up. When the issue was first reported, Google released Chrome 87, which began blocking HTTP and HTTPS access to TCP ports 5060 and 5061. Then in January of this year (2021) Google expanded their efforts, blocking HTTP, HTTPS, and FTP access to ports 69, 137, 161, 1719, 1720, 1723, and 6566.

Google has, in the past, also blocked port 554, but when they did so initially, they received push back from Enterprise users who asked that the port be unblocked. Google did so, but have now reversed course, and port 554 is once again on the blocked list.

It should also be noted that Google isn't alone. In addition to Chrome 89, Firefox 84+ and Apple's Safari browser are already blocking Port 554. So if you host a website on any of the ports mentioned above, you should reconfigure to allow visitors to continue to have unfettered access. Obviously, if you don't currently utilize that port there's nothing to do here. If you're not sure, you will be soon enough, because you're apt to get complaints from users who can no longer access your site or whatever web-based application you're running that relies on it.

Despite some back and forth on the matter, this appears to be the path forward. So kudos to Mozilla, Google and Apple for getting on the same page and putting a halt to the threat, even if it took a bit longer than usual for the major forces in the browser ecosystem to all wind up on the same page.

Tagged Under IT Operations[Cybersecurity](https://blog.securafy.com/tag/cybersecurity)Business Continuity

In This Article

Need Help With Your Current Setup?

Talk through your current systems, risks, and support gaps with Securafy.

[Book a Strategy Call](https://meetings.hubspot.com/securafy/strategy-call)

## Join The Conversation

Have a question or perspective on this topic? Add it below.

![Randy Hall](https://blog.securafy.com/hubfs/Randy%20Hall%202.png)

About The Author

Randy Hall · CEO & Founder

Randy Hall is the CEO and Founder of Securafy, with decades of experience helping organizations make smarter, safer decisions about technology.

 A frequent speaker and instructor at national IT events, Randy has advised thousands of organizations, from startups and SMBs to large enterprises and U.S. government entities, on secure, practical technology adoption. He writes about the decisions business leaders are often expected to make without enough context, including cybersecurity, compliance, AI, cyber insurance, IT strategy, and business resilience.

 Outside the office, you’ll often find Randy on Lake Erie enjoying time on his 38-foot Chris-Craft.

**Writes about:** Cybersecurity strategy, compliance, AI security, business resilience, cyber insurance, SMB risk, IT leadership

[More From This Author →](https://blog.securafy.com/author/randyhall)

Related Articles

Business Continuity [Compliance Risk Assessment: How Downtime Impacts Your Bottom Line](https://blog.securafy.com/compliance-risk-assessment-how-downtime-impacts-your-bottom-line)

When systems go down, compliance obligations don't pause—and the financial consequences ...

Jul 28, 2026

Compliance [HIPAA Security Rule Changes Are Delayed To 2027: Why Healthcare Organizations Should Not Wait](https://blog.securafy.com/hipaa-security-rule-changes-are-delayed-to-2027-why-healthcare-organizations-should-not-wait)

The updated HIPAA Security Rule won't take effect until 2027, but healthcare ...

Jul 23, 2026

Compliance [Multi Factor Authentication Best Practices for CJIS Security Policy Compliance](https://blog.securafy.com/multi-factor-authentication-best-practices-for-cjis-security-policy-compliance)

Law enforcement agencies and criminal justice organizations face mounting pressure to ...

Jul 16, 2026

Compliance [CMMC Phase II Has Been Suspended: What Defense Contractors Still Need To Do](https://blog.securafy.com/cmmc-phase-ii-has-been-suspended-what-defense-contractors-still-need-to-do)

The Department of Defense suspended CMMC Phase II enforcement, but that doesn't mean ...

Jul 15, 2026

IT Operations [Cybersecurity For Veterinary Clinics: Protecting Client Data, Payment Systems, And Practice Operations](https://blog.securafy.com/cybersecurity-for-veterinary-clinics-protecting-client-data-payment-systems-and-practice-operations)

Veterinary clinics handle sensitive client data, payment information, and critical ...

Jul 9, 2026

IT Operations [AT&T Cybersecurity, AlienVault USM, And Managed Security: What SMBs Still Need To Own](https://blog.securafy.com/att-cybersecurity-alienvault-usm-and-managed-security-what-smbs-still-need-to-own)

Managed security platforms like AT&T Cybersecurity and AlienVault USM provide ...

Jul 8, 2026

Get Practical Cybersecurity Field Notes

Monthly cybersecurity, compliance, and IT strategy updates from Securafy, written for business owners who need clear next steps.

- Practical security tips from our Cyber Security Drip series
- The Securafy Times, our monthly roundup on compliance and IT strategy
- Occasional updates on new tools, guides, and research
- No spam — unsubscribe anytime

NIST CSF 2.0 Zero Trust Application Control CISA Aligned Enterprise Partner

© 2026 Securafy — Columbus & Cleveland, Ohio

[Main Site](https://www.securafy.com/) [Blog Home](https://blog.securafy.com/) [Contact](https://www.securafy.com/contact.html) [Privacy Policy](https://www.securafy.com/privacy-policy.html)

```json
{
  "@context" : "https://schema.org",
  "@type" : "BlogPosting",
  "author" : {
    "@type" : "Person",
    "name" : "Randy Hall",
    "url" : "https://blog.securafy.com/author/randyhall"
  },
  "dateModified" : "2024-07-24T20:10:21.622Z",
  "datePublished" : "2021-03-31T15:00:00.000Z",
  "headline" : "Internet Browsers Blocking Some Ports Due To Security Vulnerabilities",
  "mainEntityOfPage" : {
    "@id" : "https://blog.securafy.com/2021/03/31/internet-browsers-blocking-some-ports-due-to-security-vulnerabilities",
    "@type" : "WebPage"
  },
  "publisher" : {
    "@type" : "Organization",
    "logo" : {
      "@type" : "ImageObject",
      "url" : "https://blog.securafy.com/hubfs/securafy-logo.png"
    },
    "name" : "Securafy Inc."
  }
}
```

```json
{
  "@context" : "https://schema.org",
  "@id" : "https://securafy.com/#organization",
  "@type" : "Organization",
  "address" : [ {
    "@type" : "PostalAddress",
    "addressLocality" : "Columbus",
    "addressRegion" : "OH",
    "postalCode" : "43219",
    "streetAddress" : "4449 Easton Way, Suite 200"
  }, {
    "@type" : "PostalAddress",
    "addressLocality" : "Independence",
    "addressRegion" : "OH",
    "postalCode" : "44131",
    "streetAddress" : "6100 Oak Tree Blvd, Suite 200"
  } ],
  "areaServed" : [ "Columbus OH", "Cleveland OH", "Ohio" ],
  "name" : "Securafy Inc.",
  "url" : "https://securafy.com/"
}
```

```json
{
  "@context" : "https://schema.org",
  "@id" : "https://securafy.com/#website",
  "@type" : "WebSite",
  "inLanguage" : "en-US",
  "name" : "Securafy",
  "publisher" : {
    "@id" : "https://securafy.com/#organization"
  },
  "url" : "https://securafy.com/"
}
```

```json
{
  "@context" : "https://schema.org",
  "@id" : "https://blog.securafy.com/#blog",
  "@type" : "Blog",
  "name" : "Securafy Knowledge Hub",
  "publisher" : {
    "@id" : "https://securafy.com/#organization"
  },
  "url" : "https://blog.securafy.com"
}
```

```json
{
  "@context" : "https://schema.org",
  "@id" : "https://blog.securafy.com/2021/03/31/internet-browsers-blocking-some-ports-due-to-security-vulnerabilities#article",
  "@type" : "Article",
  "author" : {
    "@id" : "https://www.securafy.com/about-us/#randyhall",
    "@type" : "Person",
    "name" : "Randy Hall"
  },
  "dateModified" : "2024-07-24T20:10:21+00:00",
  "datePublished" : "2021-03-31T15:00:00+00:00",
  "description" : "Internet Browsers Blocking Some Ports Due To Security Vulnerabilities",
  "headline" : "Internet Browsers Blocking Some Ports Due To Security Vulnerabilities",
  "image" : "https://www.securafy.com/hs-fs/hubfs/securafy-og-default.jpg",
  "inLanguage" : "en-US",
  "isPartOf" : {
    "@id" : "https://blog.securafy.com/#blog"
  },
  "mainEntityOfPage" : {
    "@id" : "https://blog.securafy.com/2021/03/31/internet-browsers-blocking-some-ports-due-to-security-vulnerabilities",
    "@type" : "WebPage"
  },
  "publisher" : {
    "@id" : "https://securafy.com/#organization"
  },
  "url" : "https://blog.securafy.com/2021/03/31/internet-browsers-blocking-some-ports-due-to-security-vulnerabilities"
}
```

```json
{
  "@context" : "https://schema.org",
  "@type" : "BreadcrumbList",
  "itemListElement" : [ {
    "@type" : "ListItem",
    "item" : "https://blog.securafy.com",
    "name" : "Knowledge Hub",
    "position" : 1
  }, {
    "@type" : "ListItem",
    "item" : "https://blog.securafy.com/2021/03/31/internet-browsers-blocking-some-ports-due-to-security-vulnerabilities",
    "name" : "Internet Browsers Blocking Some Ports Due To Security Vulnerabilities",
    "position" : 2
  } ]
}
```