ChromeWeb browser · Google
CVE-2016-5133
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedGoogle Chrome before 52.0.2743.82 mishandles origin information during proxy authentication, which allows man-in-the-middle attackers to spoof a proxy-authentication login prompt or trigger incorrect credential storage by modifying the client-server data stream.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceGoogle Chrome before 52.0.2743.82 incorrectly handles origin information during proxy authentication. A man-in-the-middle attacker who can modify the client-server data stream can exploit this to either spoof a proxy-authentication login prompt (potentially harvesting credentials) or cause incorrect credential storage, leading to credential leakage on subsequent connections.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
ChromeWeb browser
<= 51.0.2704.106CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Chrome versionOpen Chrome, click the menu icon (three dots), select Help, then About Google Chrome. The version number is displayed on that page. Alternatively, navigate to chrome://settings/helpAffected if Version displayed is 51.0.2704.106 or lower
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Confirm proxy authentication is configuredGo to Settings, click Advanced, scroll to System, click Open proxy settings. In Windows, check the LAN settings or Proxy tab. On macOS, check Network > Advanced > Proxies. On Linux, check Network Settings > Network proxyAffected if A proxy server is configured with authentication (username/password fields are enabled or a credential prompt has been seen)
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Verify credential storage behaviorAfter entering proxy credentials in Chrome, check if they are stored in the system's credential manager (Windows Credential Manager, macOS Keychain, or Linux libsecret). Note whether credentials persist across browser restartsAffected if Proxy credentials are stored by Chrome and persist across sessions, indicating the vulnerable credential storage behavior is active
You are affected if Chrome version is 51.0.2704.106 or lower AND you have a proxy configured that requires authentication, because the flawed origin-handling during proxy auth can cause credential leakage or prompt spoofing.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpdate Google Chrome to version 52.0.2743.82 or later. For enterprise environments, deploy the updated browser via patch management and consider enforcing proxy authentication policies to mitigate MITM risks during the update window.
Fix this in Chrome
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-5133 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2016-5133 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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