CVE-2016-4309

Exp

Session fixation vulnerability in Symphony CMS 2.6.7, when session.use_only_cookies is disabled, allows remote attackers to hijack web sessions via the PHPSESSID parameter.

Published: 2016-06-30 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-4309 is rated High Exploit Risk (73.2/100): CVSS High severity, with high exploitation likelihood (EPSS 9.42%, 95th percentile). 3 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2016-4309

EDB-ID Source Kind Published Link
39983 exploit_db edb 2016-06-20 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2016-4309

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 19.13% 9.42% -9.71%
2 2026-03-04 10.81% 19.13% +8.32%
3 2026-03-01 — 10.81% —

Full EPSS history (41 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-4309

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.6 5.9 [email protected]
7.6 2.0 HIGH
AV:N/AC:H/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:H)
Exploitation requires uncommon or highly specific conditions.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 4.9 10.0 [email protected]

Weakness enumeration for CVE-2016-4309

NVD evaluator notes for CVE-2016-4309

Comment: <a href="http://cwe.mitre.org/data/definitions/384.html">CWE-384: Session Fixation</a>

Affected software / configurations for CVE-2016-4309

Vendor Product Version Raw CPE
getsymphony symphony 2.6.7 cpe:2.3:a:getsymphony:symphony:2.6.7:*:*:*:*:*:*:*

References for CVE-2016-4309

cvelogic Threat Intelligence