CVE-2015-4050

FragmentListener in the HttpKernel component in Symfony 2.3.19 through 2.3.28, 2.4.9 through 2.4.10, 2.5.4 through 2.5.11, and 2.6.0 through 2.6.7, when ESI or SSI support enabled, does not check if the _controller attribute is set, which allows remote attackers to bypass URL signing and security rules by including (1) no hash or (2) an invalid hash in a request to /_fragment.

Published: 2015-06-02 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2015-4050 is rated Moderate Risk (50.8/100): CVSS Medium severity, with high exploitation likelihood (EPSS 76.19%, 99th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. 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-2015-4050

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 2025-05-20 77.16% 76.19% -0.97%
2 2025-05-17 73.27% 77.16% +3.89%
3 2025-03-30 — 73.27% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-4050

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/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:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2015-4050

GitHub Security Advisory for CVE-2015-4050

GHSA-qmqw-mpqp-mr54 · Severity: medium · Ecosystem: composer — Symfony Incorrect Access Control

OS Trackers for CVE-2015-4050

vendor priority summary link
debian not yet assigned CVE-2015-4050 not yet assigned priority: Debian including 1 source packages (symfony), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2015-4050
ubuntu medium CVE-2015-4050 medium priority: Ubuntu including 1 source packages (symfony), 11 status rows across 11 suites (artful, bionic, precise, trusty, upstream, utopic, vivid, wily, xenial, yakkety, zesty): ignored 5, DNE 3, not-affected 2, released 1. https://ubuntu.com/security/CVE-2015-4050

Affected software / configurations for CVE-2015-4050

Vendor Product Version Raw CPE
sensiolabs symfony 2.3.19 cpe:2.3:a:sensiolabs:symfony:2.3.19:*:*:*:*:*:*:*
sensiolabs symfony 2.3.20 cpe:2.3:a:sensiolabs:symfony:2.3.20:*:*:*:*:*:*:*
sensiolabs symfony 2.3.21 cpe:2.3:a:sensiolabs:symfony:2.3.21:*:*:*:*:*:*:*
sensiolabs symfony 2.3.22 cpe:2.3:a:sensiolabs:symfony:2.3.22:*:*:*:*:*:*:*
sensiolabs symfony 2.3.23 cpe:2.3:a:sensiolabs:symfony:2.3.23:*:*:*:*:*:*:*
sensiolabs symfony 2.3.24 cpe:2.3:a:sensiolabs:symfony:2.3.24:*:*:*:*:*:*:*
sensiolabs symfony 2.3.25 cpe:2.3:a:sensiolabs:symfony:2.3.25:*:*:*:*:*:*:*
sensiolabs symfony 2.3.26 cpe:2.3:a:sensiolabs:symfony:2.3.26:*:*:*:*:*:*:*
sensiolabs symfony 2.3.27 cpe:2.3:a:sensiolabs:symfony:2.3.27:*:*:*:*:*:*:*
sensiolabs symfony 2.3.28 cpe:2.3:a:sensiolabs:symfony:2.3.28:*:*:*:*:*:*:*
sensiolabs symfony 2.4.9 cpe:2.3:a:sensiolabs:symfony:2.4.9:*:*:*:*:*:*:*
sensiolabs symfony 2.4.10 cpe:2.3:a:sensiolabs:symfony:2.4.10:*:*:*:*:*:*:*
sensiolabs symfony 2.5.4 cpe:2.3:a:sensiolabs:symfony:2.5.4:*:*:*:*:*:*:*
sensiolabs symfony 2.5.5 cpe:2.3:a:sensiolabs:symfony:2.5.5:*:*:*:*:*:*:*
sensiolabs symfony 2.5.6 cpe:2.3:a:sensiolabs:symfony:2.5.6:*:*:*:*:*:*:*
sensiolabs symfony 2.5.7 cpe:2.3:a:sensiolabs:symfony:2.5.7:*:*:*:*:*:*:*
sensiolabs symfony 2.5.8 cpe:2.3:a:sensiolabs:symfony:2.5.8:*:*:*:*:*:*:*
sensiolabs symfony 2.5.9 cpe:2.3:a:sensiolabs:symfony:2.5.9:*:*:*:*:*:*:*
sensiolabs symfony 2.5.10 cpe:2.3:a:sensiolabs:symfony:2.5.10:*:*:*:*:*:*:*
sensiolabs symfony 2.5.11 cpe:2.3:a:sensiolabs:symfony:2.5.11:*:*:*:*:*:*:*
sensiolabs symfony 2.6.0 cpe:2.3:a:sensiolabs:symfony:2.6.0:*:*:*:*:*:*:*
sensiolabs symfony 2.6.1 cpe:2.3:a:sensiolabs:symfony:2.6.1:*:*:*:*:*:*:*
sensiolabs symfony 2.6.3 cpe:2.3:a:sensiolabs:symfony:2.6.3:*:*:*:*:*:*:*
sensiolabs symfony 2.6.4 cpe:2.3:a:sensiolabs:symfony:2.6.4:*:*:*:*:*:*:*
sensiolabs symfony 2.6.5 cpe:2.3:a:sensiolabs:symfony:2.6.5:*:*:*:*:*:*:*
sensiolabs symfony 2.6.6 cpe:2.3:a:sensiolabs:symfony:2.6.6:*:*:*:*:*:*:*
sensiolabs symfony 2.6.7 cpe:2.3:a:sensiolabs:symfony:2.6.7:*:*:*:*:*:*:*

References for CVE-2015-4050

cvelogic Threat Intelligence