CVE-2015-4520: mozilla firefox 7PK - Security Features
Vulnerability summary
CVE-2015-4520 is a medium (CVSS 6.4) 7PK - Security Features vulnerability in mozilla firefox. EPSS estimates a 2.61% chance of exploitation in the next 30 days, higher than 85.4% of scored vulnerabilities.
Not severe (CVSS 6.4, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 13 · Related 7Timeline
- 24-09-2015PublishedVulnerability first disclosed.
- 06-08-2024Last modifiedVulnerability information updated.
Description
Mozilla Firefox before 41.0 and Firefox ESR 38.x before 38.3 allow remote attackers to bypass CORS preflight protection mechanisms by leveraging (1) duplicate cache-key generation or (2) retrieval of a value from an incorrect HTTP Access-Control-* response header.
CVSS metrics
1 score · 1 source · 1 versionEPSS trend
Probability
2.61%
Chance of exploitation in the next 30 days
Percentile
85%
Versus all other CVEs
30-day change
Decrease -0.49 pp
From 3.09% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication (CVSS vector). Other conditions: not stated in public data.
Ubuntu2 products
- firefox< 41.0+build3-0ubuntu0.14.04.1
- thunderbird< 1:38.3.0+build1-0ubuntu0.14.04.1
Mozilla1 product
- firefox38.0 | 38.0.1 | 38.0.5 | 38.1.0 | 38.1.1 | 38.2.0 | 38.2.1 | ≤ 40.0.3
2 vendors · 3 products
References
26 links- www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.htmlX Refsource CONFIRM
- www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.htmlX Refsource CONFIRM
Show all 26 references
- bugzilla.mozilla.org/show_bug.cgi?id=1200856X Refsource CONFIRM
- bugzilla.mozilla.org/show_bug.cgi?id=1200869X Refsource CONFIRM
