CVE-2020-5220 | Ability to expose data in Sylius by using an unintended serialisation group

Sylius ResourceBundle accepts and uses any serialisation groups to be passed via a HTTP header. This might lead to data exposure by using an unintended serialisation group - for example it could make Shop API use a more permissive group from Admin API. Anyone exposing an API with ResourceBundle's controller is affected. The vulnerable versions are: <1.3 || >=1.3.0 <=1.3.12 || >=1.4.0 <=1.4.5 || >=1.5.0 <=1.5.0 || >=1.6.0 <=1.6.2. The patch is provided for Sylius ResourceBundle 1.3.13, 1.4.6, 1.5.1 and 1.6.3, but not for any versions below 1.3.

Published: 2020-01-27 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-5220 is rated Low Risk (35.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.74%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2020-5220

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 0.32% 0.74% +0.41%
2 2025-11-21 0.20% 0.32% +0.13%
3 2025-11-18 0.20%

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-5220

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/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: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: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:L)
Some sensitive info could get out, but not a total data dump.
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.
1.3 2.7 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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: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.
3.9 1.4 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/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: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.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-5220

GitHub Security Advisory for CVE-2020-5220

GHSA-8vp7-j5cj-vvm2 · Severity: medium · Ecosystem: composer — Ability to expose data in Sylius by using an unintended serialisation group

Affected software / configurations for CVE-2020-5220

Vendor Product Version Raw CPE
sylius syliusresourcebundle >= 1.3.0, <= 1.3.12 cpe:2.3:a:sylius:syliusresourcebundle:*:*:*:*:*:*:*:*
sylius syliusresourcebundle >= 1.4.0, <= 1.4.5 cpe:2.3:a:sylius:syliusresourcebundle:*:*:*:*:*:*:*:*
sylius syliusresourcebundle >= 1.6.0, <= 1.6.2 cpe:2.3:a:sylius:syliusresourcebundle:*:*:*:*:*:*:*:*
sylius syliusresourcebundle 1.5.0 cpe:2.3:a:sylius:syliusresourcebundle:1.5.0:*:*:*:*:*:*:*

References for CVE-2020-5220

cvelogic Threat Intelligence