CVE-2014-8639

medium

Published 2015-01-14 · Modified 2026-05-06

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CVSS v3

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CVSS v4 NEW

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not yet in upstream

VIR risk

6.8

Description

Mozilla Firefox before 35.0, Firefox ESR 31.x before 31.4, Thunderbird before 31.4, and SeaMonkey before 2.32 do not properly interpret Set-Cookie headers within responses that have a 407 (aka Proxy Authentication Required) status code, which allows remote HTTP proxy servers to conduct session fixation attacks by providing a cookie name that corresponds to the session cookie of the origin server.

Predictions

Exploit likelihood

20%

Patch ETA

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Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Application impact

Vendor	Product	Versions
mozilla	seamonkey	`{"endIncluding":"2.31"}`
mozilla	firefox	`{"endIncluding":"34.0.5"}`
mozilla	firefox	`31.0`
mozilla	firefox	`31.1.0`
mozilla	firefox	`31.1.1`
mozilla	firefox	`31.3.0`
mozilla	firefox_esr	`31.2`
mozilla	thunderbird	`{"endIncluding":"31.3.0"}`

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.