CVE-2016-9417

The fetch_remote_file function in MyBB (aka MyBulletinBoard) before 1.8.8 and MyBB Merge System before 1.8.8 allows remote attackers to conduct server-side request forgery (SSRF) attacks via unspecified vectors.

Published: 2017-01-31 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2016-9417 is rated Moderate Risk (54.2/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.65%). Mandatory action: Review affected assets and schedule 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-2016-9417

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 2025-03-17 0.22% 0.65% +0.44%
2 2023-03-07 1.21% 0.22% -1.00%
3 2022-02-04 1.21%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-9417

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.4 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 4.0 [email protected]
5.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
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:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
8.6 4.9 [email protected]

Weakness enumeration for CVE-2016-9417

Affected software / configurations for CVE-2016-9417

Vendor Product Version Raw CPE
mybb merge_system <= 1.8.7 cpe:2.3:a:mybb:merge_system:*:*:*:*:*:*:*:*
mybb mybb <= 1.8.7 cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:*

References for CVE-2016-9417

URL Tags
http://www.openwall.com/lists/oss-security/2016/11/10/8 Mailing List Patch Third Party Advisory
http://www.openwall.com/lists/oss-security/2016/11/18/1 Mailing List Patch Third Party Advisory
http://www.securityfocus.com/bid/94396 Third Party Advisory VDB Entry
https://blog.mybb.com/2016/10/17/mybb-1-8-8-merge-system-1-8-8-release/ Patch Release Notes Vendor Advisory
cvelogic Threat Intelligence