CVE-2020-5275 | Firewall configured with unanimous strategy was not actually unanimous in symfony/security-http

In symfony/security-http before versions 4.4.7 and 5.0.7, when a `Firewall` checks access control rule, it iterate overs each rule's attributes and stops as soon as the accessDecisionManager decides to grant access on the attribute, preventing the check of next attributes that should have been take into account in an unanimous strategy. The accessDecisionManager is now called with all attributes at once, allowing the unanimous strategy being applied on each attribute. This issue is patched in versions 4.4.7 and 5.0.7.

Published: 2020-03-30 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-5275 is rated Moderate Risk (53.2/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.15%). 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-2020-5275

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 0.27% 1.15% +0.87%
2 2025-03-30 0.51% 0.27% -0.23%
3 2025-03-29 0.51%

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-5275

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/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:L)
A normal user session is enough; they don’t have to be admin.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.3 4.7 [email protected]
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/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: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: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:N)
Service keeps running; no real outage angle.
2.8 5.2 [email protected]
5.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
8.0 4.9 [email protected]

Weakness enumeration for CVE-2020-5275

GitHub Security Advisory for CVE-2020-5275

GHSA-g4m9-5hpf-hx72 · Severity: high · Ecosystem: composer — Firewall configured with unanimous strategy was not actually unanimous in Symfony

OS Trackers for CVE-2020-5275

vendor priority summary link
debian not yet assigned CVE-2020-5275 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-2020-5275
ubuntu medium CVE-2020-5275 medium priority: Ubuntu including 1 source packages (symfony), 10 status rows across 10 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, trusty, upstream, xenial): not-affected 7, DNE 1, ignored 1, released 1. https://ubuntu.com/security/CVE-2020-5275

Affected software / configurations for CVE-2020-5275

Vendor Product Version Raw CPE
sensiolabs symfony >= 4.4.0, < 4.4.7 cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*
sensiolabs symfony >= 5.0.0, < 5.0.7 cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*

References for CVE-2020-5275

cvelogic Threat Intelligence