CVE-2016-3321

Microsoft Internet Explorer 10 and 11 load different files for attempts to open a file:// URL depending on whether the file exists, which allows local users to enumerate files via vectors involving a file:// URL and an HTML5 sandbox iframe, aka "Internet Explorer Information Disclosure Vulnerability."

Published: 2016-08-09 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2016-3321 is rated Moderate Risk (49.4/100): CVSS Low severity, with high exploitation likelihood (EPSS 35.33%, 98th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +6.65% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-3321

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 28.68% 35.33% +6.65%
2 2025-11-18 29.81% 28.68% -1.14%
3 2025-08-23 29.81%

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-3321

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
2.5 3.0 LOW
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
1.0 1.4 [email protected]
1.9 2.0 LOW
AV:L/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
3.4 2.9 [email protected]

Weakness enumeration for CVE-2016-3321

Affected software / configurations for CVE-2016-3321

Vendor Product Version Raw CPE
microsoft internet_explorer 10 cpe:2.3:a:microsoft:internet_explorer:10:*:*:*:*:*:*:*
microsoft internet_explorer 11 cpe:2.3:a:microsoft:internet_explorer:11:-:*:*:*:*:*:*

References for CVE-2016-3321

cvelogic Threat Intelligence