Skip to content
https://teamviewer.com

Security

· 12 checks — HTTP headers, CSP, TLS handshake, and cookie hygiene rolled into one auditable list.
SCORE
84
GRADE
B
FIX
2
REVIEW
2
PASS
8
INFO
0
Checks
12
8 PASS 2 REVIEW 2 FIX
D
Subresource Integrity
Action
1 of 8 external resources have SRI
FIX
1 of 8 external resources have SRI
Info::
script from www.gstatic.com has SRI protection
Warning::
External script from assets.adobedtm.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: //assets.adobedtm.com/439d99b3b8f0/eec744300fc5/launch-7638b87287c1.min.js
Warning::
External script from www.google.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://www.google.com/recaptcha/api.js?render=6Le3mt4fAAAAAJiufWYTj3EU2lhCLwN14M91EqP9
Warning::
External script from cdn.cookielaw.org lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://cdn.cookielaw.org/scripttemplates/otSDKStub.js
Warning::
External script from cdn.cookielaw.org lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://cdn.cookielaw.org/scripttemplates/202601.2.0/otBannerSdk.js
Warning::
External script from assets.adobedtm.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://assets.adobedtm.com/439d99b3b8f0/eec744300fc5/8d6035e58044/RCac64c34110bb4c49b2c490d75257bdc8-source.min.js
Warning::
External script from assets.adobedtm.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://assets.adobedtm.com/439d99b3b8f0/eec744300fc5/8d6035e58044/RC3a76c8b87ef040d88b98d5caf0f18dc7-source.min.js
Warning::
External script from assets.adobedtm.com lacks integrity attribute
Without SRI, if this CDN is compromised, attackers could inject malicious code.
Got: https://assets.adobedtm.com/439d99b3b8f0/eec744300fc5/8d6035e58044/RC778a8cff007f41c79b09d8a915146e5c-source.min.js
SRI Coverage 1 / 8 of external resources have integrity hashes
TagDomainIntegrity
<script>www.gstatic.com✓ Protected
<script>assets.adobedtm.com✗ Missing
<script>www.google.com✗ Missing
<script>cdn.cookielaw.org✗ Missing
<script>cdn.cookielaw.org✗ Missing
<script>assets.adobedtm.com✗ Missing
<script>assets.adobedtm.com✗ Missing
<script>assets.adobedtm.com✗ Missing
D
Permissions-Policy
Action
No header set
FIX
No header set
Warning::
No Permissions-Policy header
Consider adding a Permissions-Policy header to restrict browser feature access from embedded content.

No Permissions-Policy header set.

Without this header, embedded iframes can request access to sensitive device features.

Suggested header
Permissions-Policy: camera=(), microphone=(), geolocation=(), payment=(), usb=()
B
Security Headers
7 of 10 headers properly configured
REVIEW
7 of 10 headers properly configured
Info::
Strict-Transport-Security is properly configured (consider adding preload)
Got: max-age=31536000; includeSubDomains;
Info::
X-Content-Type-Options is properly configured
Got: nosniff
Info::
X-Frame-Options is properly configured
Got: SAMEORIGIN
Info::
Referrer-Policy is properly configured
Got: no-referrer-when-downgrade
Warning::
Permissions-Policy header is missing
Controls which browser features (camera, microphone, geolocation) are allowed. Set it to restrict unused features.
Expected: geolocation=(), camera=(), microphone=()
Info::
Content-Security-Policy is present
Got: default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame…
Warning::
Cross-Origin-Opener-Policy header is missing
COOP isolates your browsing context, preventing cross-origin side-channel attacks. Set to 'same-origin'.
Expected: same-origin
Warning::
Cross-Origin-Embedder-Policy header is missing
COEP prevents loading cross-origin resources without explicit permission. Required for SharedArrayBuffer and high-resolution timers.
Expected: require-corp
Info::
X-Powered-By header is not present
Info::
Server header is present without version info
Got: nginx

Controls which browser features (camera, microphone, geolocation) are allowed. Set it to restrict unused features.

Expected: geolocation=(), camera=(), microphone=()
Why this matters

Permissions-Policy locks down browser APIs you don't use — without it, every page can request camera/mic/geolocation if XSS lands.

Learn more ▾

By default every page can request the camera, microphone, geolocation, payment APIs, and dozens more. Permissions-Policy turns off the ones you don't need so a future bug can't quietly start using them. It's a defense-in-depth header — one line, big surface reduction.

Source: MDN / W3C

COOP isolates your browsing context, preventing cross-origin side-channel attacks. Set to 'same-origin'.

Expected: same-origin
Why this matters

COOP isolates your top-level browsing context from cross-origin windows — without it, popup-based side-channel attacks remain possible.

Learn more ▾

Cross-Origin-Opener-Policy: same-origin prevents cross-origin pages from sharing a browsing-context group with yours. This blocks cross-window references that enable Spectre-style timing attacks and tab-nabbing. Required if you want to enable SharedArrayBuffer.

Source: MDN / web.dev

COEP prevents loading cross-origin resources without explicit permission. Required for SharedArrayBuffer and high-resolution timers.

Expected: require-corp
Why this matters

COEP enforces that all embedded resources opt-in to cross-origin embedding — required for cross-origin isolation features.

Learn more ▾

Cross-Origin-Embedder-Policy: require-corp ensures every embedded resource (script, iframe, image) explicitly allows being loaded cross-origin. Combined with COOP, this enables the cross-origin-isolated context that unlocks SharedArrayBuffer, high-resolution timers, and other powerful APIs.

Source: MDN / web.dev

B
CORS Configuration
No CORS headers
REVIEW
No CORS headers
Info::
No CORS headers present — secure default
CORS Configuration ✓ Secure

No CORS headers detected.

Cross-origin requests are blocked by browser same-origin policy.

Origin reflection test

Some servers mirror the request Origin header, which can be exploited. Test manually:

curl -sI -H "Origin: https://evil.com" <url> | grep -i access-control
A
Content Security Policy
7 of 10 CSP checks passed
PASS
7 of 10 CSP checks passed
Info::
Raw CSP policy
Got: default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'none'
Info::
default-src directive is set
Got: default-src 'self'
Info::
No 'unsafe-inline' in script source
Info::
No 'unsafe-eval' in script source
Info::
No wildcard in script source
Info::
object-src is set to 'none'
Got: object-src 'none'
Info::
base-uri is properly restricted
Got: base-uri 'self'
Info::
frame-ancestors directive is set
Got: frame-ancestors 'none'
Warning::
form-action directive is missing
form-action restricts where forms can submit data, preventing form hijacking.
Expected: form-action 'self'
Info::
upgrade-insecure-requests is not set
This directive upgrades HTTP resources to HTTPS automatically, preventing mixed content.
Expected: upgrade-insecure-requests

form-action restricts where forms can submit data, preventing form hijacking.

Expected: form-action 'self'
Why this matters

Security gaps expose your site and users to attacks, eroding trust.

This directive upgrades HTTP resources to HTTPS automatically, preventing mixed content.

Expected: upgrade-insecure-requests
Why this matters

Without upgrade-insecure-requests, any HTTP subresource link survives as a mixed-content warning instead of auto-upgrading.

Learn more ▾

Adding `upgrade-insecure-requests` to your CSP turns every http:// subresource fetch into https:// at the browser layer. One-line defense against accidental mixed content from legacy links or third-party widgets.

Source: MDN CSP

Parsed Policy

default-src 'self'
script-src 'self'
object-src 'none'
base-uri 'self'
frame-ancestors 'none'
A+
TLS & Certificates
TLS 1.3, 7 checks passed
PASS
TLS 1.3, 7 checks passed
Info::
TLS 1.3 is used
Got: TLS 1.3
Info::
Strong cipher suite is used
Got: TLS_AES_128_GCM_SHA256
Info::
HTTP/2 is not negotiated
HTTP/2 provides multiplexing and header compression for better performance.
Got: http/1.1
Info::
Certificate is valid (expires in 37 days)
Got: 2026-05-23T23:59:59Z
Info::
Certificate chain has 4 certificates
Info::
Certificate uses modern signature algorithm
Got: SHA256-RSA
Info::
Certificate covers 2 domain(s)
Got: *.teamviewer.com, teamviewer.com
Info::
Certificate is issued by a trusted CA
Got: CN=Sectigo RSA Domain Validation Secure Server CA,O=Sectigo Limited,L=Salford,ST=Greater Manchester,C=GB

HTTP/2 provides multiplexing and header compression for better performance.

Why this matters

HTTP/1.1 forces the browser to make sequential requests, multiplying latency on every page.

Learn more ▾

HTTP/2 (and HTTP/3) multiplex many requests over a single connection, eliminating head-of-line blocking. HTTP/1.1 forces the browser to either queue requests or open many parallel connections — both worse. Most modern web servers support HTTP/2 with one config line.

Source: MDN Web Docs

Connection
Protocol
TLS 1.3
Cipher Suite
TLS_AES_128_GCM_SHA256
HTTP Version
HTTP/1.1

Certificate Chain

Leaf Certificate
Subject CN=*.teamviewer.comIssuer CN=Sectigo RSA Domain Validation Secure Server CA,O=Sectigo Limited,L=Salford,ST=Greater Manchester,C=GBValid 2025-04-22T00:00:00Z → 2026-05-23T23:59:59ZExpires in 37 days SANs *.teamviewer.com, teamviewer.comSignature SHA256-RSASerial 23b5491b68463756ce5b170bbc97315d
Intermediate (CA Certificate)
Subject CN=Sectigo RSA Domain Validation Secure Server CA,O=Sectigo Limited,L=Salford,ST=Greater Manchester,C=GBIssuer CN=USERTrust RSA Certification Authority,O=The USERTRUST Network,L=Jersey City,ST=New Jersey,C=USValid 2018-11-02T00:00:00Z → 2030-12-31T23:59:59ZExpires in 1720 days Signature SHA384-RSASerial 7d5b5126b476ba11db74160bbc530da7
Intermediate (CA Certificate)
Subject CN=USERTrust RSA Certification Authority,O=The USERTRUST Network,L=Jersey City,ST=New Jersey,C=USIssuer CN=AAA Certificate Services,O=Comodo CA Limited,L=Salford,ST=Greater Manchester,C=GBValid 2019-03-12T00:00:00Z → 2028-12-31T23:59:59ZExpires in 990 days Signature SHA384-RSASerial 3972443af922b751d7d36c10dd313595
Intermediate (CA Certificate)
Subject CN=AAA Certificate Services,O=Comodo CA Limited,L=Salford,ST=Greater Manchester,C=GBIssuer CN=AAA Certificate Services,O=Comodo CA Limited,L=Salford,ST=Greater Manchester,C=GBValid 2004-01-01T00:00:00Z → 2028-12-31T23:59:59ZExpires in 990 days Signature SHA1-RSASerial 1
A+
Cookie Security
No cookies set — no cookie security risks
PASS
No cookies set — no cookie security risks
Info::
No cookies set — no cookie security risks

No cookies detected — no cookie security risks to report.

A+
JS Library Vulnerabilities
No known vulnerabilities
PASS
No known vulnerabilities
Info::
No known JavaScript library vulnerabilities detected

No known JavaScript library vulnerabilities detected.

A+
Information Leakage
No exposures
PASS
No exposures
Info::
security.txt is present — good practice
Info::
No sensitive files exposed

No sensitive files exposed — all paths returned 404.

PathStatusCategoryRisk
/.git/HEAD✓ Not foundVersion Control—
/.git/config✓ Not foundVersion Control—
/.svn/entries✓ Not foundVersion Control—
/.env✓ Not foundConfiguration—
/.env.local✓ Not foundConfiguration—
/.env.production✓ Not foundConfiguration—
/wp-config.php✓ Not foundConfiguration—
/.htaccess✓ Not foundConfiguration—
/phpinfo.php✓ Not foundDebug—
/server-status✓ Not foundDebug—
/server-info✓ Not foundDebug—
/.well-known/security.txt✗ ExposedSecurity PolicyInfo
A+
Email Security
DMARC: reject
PASS
DMARC: reject
Info::
DMARC policy is reject — strongest protection
DMARC
Policy reject — strongest protection Record v=DMARC1; p=reject; fo=1; rua=mailto:d9a924adbe@rua.easydmarc.eu; ruf=mailto:d9a924adbe@ruf.easydmarc.eu; pct=100;
A+
security.txt
Signed, 4 contact(s) — RFC 9116 compliant
PASS

security.txt

Contact: https://www.first.org/members/teams/teamviewer_sirt, https://yeswehack.com/programs/teamviewer-bounty-program, https://vdp.teamviewer.com, mailto:psirt@teamviewer.com
Expires: 2027-03-24T10:00:00.000Z
Encryption: https://keys.openpgp.org/search?q=psirt%40teamviewer.com
Policy: https://www.teamviewer.com/.well-known/security.txt
A
Transport Security
HTTP/3, HSTS, and TLS version analysis
PASS
HTTP/3, HSTS, and TLS version analysis
Info::
HTTP/3 (QUIC) not advertised
HTTP/3 eliminates head-of-line blocking. If your CDN supports it, consider enabling it.
Info::
HSTS enabled (includeSubDomains)
Info::
TLS 1.3 in use (fastest handshake, 1-RTT)
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

Send Feedback