Mac Os XOperating system · Apple

CVE-2015-5841

MEDIUM · 5.0 CVSS v2.0 Published 2015-09-18
Fix available
A fix is available. Upgrade to after 10.10.5 or later.
See remediation →
59/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

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 · unedited
The CFNetwork Proxies component in Apple iOS before 9 does not properly handle a Set-Cookie header within a response to an HTTP CONNECT request, which allows remote proxy servers to conduct cookie-injection attacks via a crafted response.

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 · high confidence

The CFNetwork Proxies component in iOS versions before 9 fails to properly validate Set-Cookie headers received in responses to HTTP CONNECT requests. This allows a malicious proxy server to inject arbitrary cookies into the client's session, which the iOS device will accept as legitimate, leading to session hijacking or authentication bypass.

MitigationUpgrade all iOS devices to version 9 or later. For legacy systems that cannot be upgraded, consider network segmentation to limit proxy exposure or implement additional application-layer cookie validation.

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
Mac Os XOperating system
Affected:<= 10.10.5
Iphone OsOperating system
Affected:<= 8.4.1
WatchosOperating system
Affected:= 1.0

CVSS 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
Low
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None

AV:N/AC:L/Au:N/C:N/I:P/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check iOS version on iPhone or iPad
    Go to Settings > General > About > Version. Note the version number displayed.
    Affected if The version is 8.4.1 or lower (e.g., 8.4, 8.3, 8.2, etc.)
  2. Check macOS version
    Click the Apple menu > About This Mac. Note the version number under the macOS name.
    Affected if The version is 10.10.5 or lower (e.g., 10.10.4, 10.10.3, etc.)
  3. Check watchOS version on Apple Watch
    On the paired iPhone, open the Watch app > My Watch > General > About. Note the watchOS version.
    Affected if The version is exactly 1.0 (only version 1.0 is listed as affected for watchOS)
  4. Determine if proxy settings are configured
    On iOS: Settings > Wi-Fi > tap the info (i) icon next to a network > HTTP Proxy section. On macOS: System Preferences > Network > select a service > Advanced > Proxies. Check if any proxy (HTTP, HTTPS, Proxy Auto-Config, or automatic proxy discovery) is enabled.
    Affected if Any proxy configuration is enabled on the device - the vulnerability allows a malicious proxy to inject cookies, so active proxy usage increases exposure but the vulnerable code path exists regardless

You are affected if your device runs iOS 8.4.1 or lower, macOS 10.10.5 or lower, or watchOS 1.0, and the device has any proxy settings configured or may connect to untrusted networks with proxies.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Upgrade available Upgrade to a release after 10.10.5
Interim mitigation

Upgrade all iOS devices to version 9 or later. For legacy systems that cannot be upgraded, consider network segmentation to limit proxy exposure or implement additional application-layer cookie validation.

Fix this in Mac Os X Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2015-5841 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data