Site report for https://stackoverflow.com
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| Site title | Stack Overflow - Where Developers Learn, Share, & Build Careers |
|---|---|
| Site rank | 46 |
| Description | Stack Overflow is the largest, most trusted online community for developers to learn, share\342\200\213 \342\200\213their programming \342\200\213knowledge, and build their careers. |
| Date first seen | November 1999 |
|---|---|
| Netcraft Risk Rating | 0/10 |
| Primary language | English |
| Site | https://stackoverflow.com |
|---|---|
| Netblock Owner | Fastly |
| Domain | stackoverflow.com |
| Nameserver | ns-1033.awsdns-01.org |
| IP address | 151.101.1.69 (VirusTotal) |
| DNS admin | awsdns-hostmaster@amazon.com |
| IPv6 address | Not Present |
| Reverse DNS | unknown |
| Domain registrar | name.com |
|---|---|
| Nameserver organisation | whois.pir.org |
| Organisation | Stack Exchange, Inc., 110 William St , Floor 28, New York, 10038, United States |
| Hosting company | unknown |
| Top Level Domain | Commercial entities (.com) |
| DNS Security Extensions | unknown |
| Hosting country | US |
| IP range | Country | Name | Description |
|---|---|---|---|
| 0.0.0.0-255.255.255.255 | N/A | IANA-BLK | The whole IPv4 address space |
| ↳ 151.0.0.0-151.255.255.255 | Netherlands | RIPE-ERX-151 | RIPE Network Coordination Centre |
| ↳ 151.101.0.0-151.101.255.255 | United States | SKYCA-3 | Fastly |
| ↳ 151.101.1.69 | United States | SKYCA-3 | Fastly |
| Assurance | Domain validation |
|---|---|
| Common name | *.stackexchange.com |
| Organisation | Not Present |
| State | Not Present |
| Country | Not Present |
| Organisational unit | Not Present |
| Subject Alternative Name | *.askubuntu.com, *.blogoverflow.com, *.mathoverflow.net, *.meta.stackexchange.com, *.meta.stackoverflow.com, *.serverfault.com, *.sstatic.net, *.stackexchange.com, *.stackoverflow.com, *.stackoverflow.email, *.superuser.com, askubuntu.com, blogoverflow.com, mathoverflow.net, openid.stackauth.com, serverfault.com, sstatic.net, stackapps.com, stackauth.com, stackexchange.com, stackoverflow.blog, stackoverflow.com, stackoverflow.email, stacksnippets.net, superuser.com |
| Validity period | From Mar 3 2020 to Jun 1 2020 (2 months, 4 weeks, 1 day) |
| Matches hostname | Yes |
| Server | Varnish |
| Public key algorithm | rsaEncryption |
| Protocol version | TLSv1.2 |
| Public key length | 2048 |
| Certificate check | ok |
| Signature algorithm | sha256WithRSAEncryption |
| Serial number | 0x0312a85b4142d24485783fb47a865d46a83a |
| Cipher | ECDHE-RSA-AES128-GCM-SHA256 |
| Version number | 0x02 |
| Perfect Forward Secrecy | Yes |
|---|---|
| Next Protocol Negotiation | Not Present |
| Supported TLS Extensions | RFC5746 renegotiation info, RFC4366 server name, RFC4492 EC point formats, RFC5077 session ticket, RFC4366 status request, unknown |
| Issuing organisation | Let's Encrypt |
| Issuer common name | Let's Encrypt Authority X3 |
| Issuer unit | Not Present |
| Issuer location | Not Present |
| Issuer country | US |
| Issuer state | Not Present |
| Certificate Revocation Lists | Not Present |
| Certificate Hash | 3V7wtk75yiOobRVMe+VOuFyjoes |
| Public Key Hash | ca70c01b1945381ce3665baa7663ee4d3196283646fad7b22327f2f1e8510c50 |
| OCSP servers | http://ocsp.int-x3.letsencrypt.org - 100% uptime in the past 24 hours |
| OCSP stapling response | Certificate valid |
| OCSP data generated | Apr 2 15:00:00 2020 GMT |
| OCSP data expires | Apr 9 15:00:00 2020 GMT |
Signed Certificate Timestamps (SCTs)
| Source | Log | Timestamp | Signature Verification |
|---|---|---|---|
| Certificate | Let's Encrypt Oak 2020 5xLysDd+GmL7jskMYYTx6ns3y1YdESZb8+DzS/JBVG4= |
2020-03-03 15:52:01 | Success |
| Certificate | Google Argon 2020 sh4FzIuizYogTodm+Su5iiUgZ2va+nDnsklTLe+LkF4= |
2020-03-03 15:52:01 | Success |
SSLv3/POODLE
This site does not support the SSL version 3 protocol.
More information about SSL version 3 and the POODLE vulnerability.
Heartbleed
The site offered the Heartbeat TLS extension prior to the Heartbleed disclosure, but is using a new certificate and no longer offers Heartbeat.
This test does not exploit the Heartbleed vulnerability but uses information from conventional HTTPS requests. More information about Heartbleed detection.
| Common name | DST Root CA X3 |
|---|---|
| Organisational unit | Not Present |
| Organisation | Digital Signature Trust Co. |
| Validity period | From 2000-09-30 to 2021-09-30 |
| Common name | Let's Encrypt Authority X3 |
|---|---|
| Organisational unit | Not Present |
| Organisation | Let's Encrypt |
| Validity period | From 2016-03-17 to 2021-03-17 |
| Netblock owner | IP address | OS | Web server | Last seen |
|---|---|---|---|---|
| Fastly PO Box 78266 San Francisco CA US 94107 | 151.101.193.69 | Linux | unknown | 6-Apr-2020 |
| Fastly PO Box 78266 San Francisco CA US 94107 | 151.101.129.69 | Linux | unknown | 29-Mar-2020 |
| Fastly PO Box 78266 San Francisco CA US 94107 | 151.101.193.69 | Linux | unknown | 21-Mar-2020 |
| Fastly PO Box 78266 San Francisco CA US 94107 | 151.101.1.69 | Linux | unknown | 13-Mar-2020 |
| Fastly PO Box 78266 San Francisco CA US 94107 | 151.101.65.69 | Linux | unknown | 5-Mar-2020 |
| Fastly PO Box 78266 San Francisco CA US 94107 | 151.101.1.69 | Linux | unknown | 25-Feb-2020 |
| Fastly PO Box 78266 San Francisco CA US 94107 | 151.101.129.69 | Linux | unknown | 22-Feb-2020 |
| Fastly PO Box 78266 San Francisco CA US 94107 | 151.101.65.69 | Linux | unknown | 5-Feb-2020 |
| Fastly PO Box 78266 San Francisco CA US 94107 | 151.101.193.69 | Linux | unknown | 23-Jan-2020 |
| Fastly PO Box 78266 San Francisco CA US 94107 | 151.101.65.69 | Linux | unknown | 11-Jan-2020 |
A host's Sender Policy Framework (SPF) describes who can send mail on its behalf. This is done by publishing an SPF record containing a series of rules. Each rule consists of a qualifier followed by a specification of which domains to apply this qualifier to. For more information please see open-spf.org.
| Qualifier | Mechanism | Argument |
|---|---|---|
| + (Pass) | ip4 | 198.252.206.0/24 |
| + (Pass) | ip4 | 192.111.0.0/24 |
| + (Pass) | ip4 | 52.38.191.241 |
| + (Pass) | ip4 | 35.190.247.0/24 |
| + (Pass) | ip4 | 64.233.160.0/19 |
| + (Pass) | ip4 | 66.102.0.0/20 |
| + (Pass) | ip4 | 66.249.80.0/20 |
| + (Pass) | ip4 | 72.14.192.0/18 |
| + (Pass) | ip4 | 74.125.0.0/16 |
| + (Pass) | ip4 | 108.177.8.0/21 |
| + (Pass) | ip4 | 173.194.0.0/16 |
| + (Pass) | include | _spf1.stackoverflow.com |
| ~ (SoftFail) | all |
DMARC (Domain-based Message Authentication, Reporting and Conformance) is a mechanism for domain owners to indicate how mail purporting to originate from their domain should be authenticated. It builds on SPF and DKIM, providing a method to set policy and to give reporting of failures. For more information please see dmarc.org.
Raw DMARC record:
v=DMARC1;p=reject;sp=reject;pct=100;rua=mailto:dmarc-aggregates@stackoverflow.com;ruf=mailto:dmarc-forensics@stackoverflow.com;fo=1
| Tag | Field | Value |
|---|---|---|
| p=reject | Requested handling policy | Reject: emails that fail the DMARC mechanism check should be rejected. Rejection SHOULD occur during the SMTP transaction. |
| sp=reject | Requested handling policy for subdomains | Reject: emails that fail the DMARC mechanism check should be rejected. Rejection SHOULD occur during the SMTP transaction. |
| pct=100 | Sampling rate | 100% of messages from the Domain Owner's mail stream should have DMARC applied. |
| rua=mailto:dmarc-aggregates@stackoverflow.com | Reporting URI(s) for aggregate data | dmarc-aggregates@stackoverflow.com |
| ruf=mailto:dmarc-forensics@stackoverflow.com | Reporting URI(s) for failure data | dmarc-forensics@stackoverflow.com |
| fo=1 | Failure reporting options | Generate a DMARC failure report if any underlying authentication mechanism failed to produce an aligned "pass" result. |
Web Trackers are third-party resources loaded onto a webpage. Trackable resources include social sharing widgets, javascript files, and images. These trackers can be used to monitor individual user behaviour across the web. Data derived from these trackers are primarily used for advertising or analytics purposes.
2 known trackers were identified.| Company | Primary Category | Tracker | Popular Sites with this Tracker |
|---|---|---|---|
| CDN | Googlecdn | www.asus.com, www.upwork.com, www.etoro.com | |
| Quantcast | Analytics | Quantcast | www.dailykos.com, www.mediafire.com, www.legacy.com |
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Any network related service or technology.
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A web accelerator is a proxy server that reduces web site access times.
Technology Description Popular sites using this technology Varnish An HTTP accelerator for web applications www.lastampa.it, www.bbc.co.uk, www.cnn.com -
Includes all the main technologies that Netcraft detects as running on the server such as PHP.
Technology Description Popular sites using this technology XML No description www.20minutes.fr, api.popin.cc, tag.sp.advertising.com SSL A cryptographic protocol providing communication security over the Internet -
Includes all the main technologies that run on the browser (such as JavaScript and Adobe Flash).
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Frameworks or libraries allow for easier development of applications by providing an Application Program Interface (API) or a methodology to follow whilst developing.
Technology Description Popular sites using this technology jQuery A JavaScript library used to simplify the client-side scripting of HTML www.amazon.ca, www.amazon.fr, www.arco.co.uk -
A content delivery network or content distribution network (CDN) is a large distributed system of servers deployed in multiple data centers in the Internet. The goal of a CDN is to serve content to end-users with high availability and high performance.
Technology Description Popular sites using this technology Google Hosted Libraries Google API to retrieve JavaScript libraries www.tunisia-sat.com, www.mediafire.com, www.reverso.net -
RSS Rich Site Summary is a family of web feed formats used to publish frequently updated works such as blog entries, news headlines, audio, and video in a standardized format.
Technology Description Popular sites using this technology Atom An XML language and HTTP protocol used in web publishing www.theregister.co.uk, www.w3.org, www.heise.de -
A web search engine is a software that is designed to search for information on the World Wide Web or on a specific site.
Technology Description Popular sites using this technology Custom Search Engine Google Custom Search Engine www.slideshare.net, www.researchgate.net, www.airbnb.com -
Web analytics is the measurement, collection, analysis and reporting of internet data for purposes of understanding and optimizing web usage.
Technology Description Popular sites using this technology Scorecard Research No description www.drugs.com, www.walmart.ca, www.laptopmag.com -
HTTP compression is a capability that can be built into web servers and web clients to make better use of available bandwidth, and provide greater transmission speeds between both.
Technology Description Popular sites using this technology Gzip Content Encoding Gzip HTTP Compression protocol www.tsetmc.com, www.seznam.cz, www.mathworks.com -
Web browser targeting enables software applications to make use of specific functions of the browser as well as optimizing the application for specific browser versions.
Technology Description Popular sites using this technology Strict Transport Security Web security policy mechanism whereby a web server declares that complying user agents are to interact with it using only secure HTTP connections www.linkedin.com, www.paypal.com, login.microsoftonline.com X-Frame-Options Same Origin Do not allow this site to be rendered within an iframe www.bitmex.com, www.google.com, vars.hotjar.com Content Security Policy Detect and mitigate attacks in the browser teams.microsoft.com, dtm.advertising.com, accounts.google.com -
A Document Type Declaration, or DOCTYPE, is an instruction that associates a particular SGML or XML document (for example, a webpage) with a Document Type Definition (DTD).
Technology Description Popular sites using this technology HTML5 Latest revision of the HTML standard, the main markup language on the web www.googleadservices.com, medium.com, disqus.com -
HTML5 is a markup language for structuring and presenting content for the World Wide Web and a core technology of the Internet. It is the fifth revision of the HTML standard.
Technology Description Popular sites using this technology Viewport meta tag HTML5 tag usually used for mobile optimization -
Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation semantics (the look and formatting) of a document written in a markup language (such as XHTML).
Technology Description Popular sites using this technology External Styles defined within an external CSS file www.microsoft.com, www.facebook.com, www.amazon.co.uk