Threats / Mozilla / CVE-2015-4495
CVE-2015-4495
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Mozilla Firefox vulnerability
Firefox vulnerability allowing remote attackers to bypass Same Origin Policy and read arbitrary files or gain elevated privileges.
Verdict
Today item — known-exploited.
A Same Origin Policy bypass in Firefox enables remote code execution and unauthorized file access. The vulnerability was actively exploited in the wild, affecting user confidentiality and system integrity across Firefox installations.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
4 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-05-25).
Probability (EPSS)
EPSS 0.70226 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Mozilla, Firefox. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-200 Information Exposure — weakness family: Authorization / access control.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious webpage that exploits the SOP bypass to access files or resources from other origins.
Business
User data confidentiality is compromised; sensitive files become accessible to unauthorized parties.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I escalate privileges by leveraging the policy bypass to execute code with elevated permissions within the browser context.
Business
System integrity is degraded; attackers gain control sufficient to install malware or exfiltrate credentials.
3
Lateral reach — past segmentation narrative 3
Attacker
I distribute the exploit through compromised websites or watering hole attacks to maximize victim reach.
Business
Widespread compromise of user bases; incident response and remediation costs escalate across affected organizations.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05