CVE-2020-5274 [Medium] | Security Vulnerability in Symfony

In Symfony before versions 5.0.5 and 4.4.5, some properties of the Exception were not properly escaped when the `ErrorHandler` rendered it stacktrace. In addition, the stacktrace were displayed even in a non-debug configuration. The ErrorHandler now escape alls properties of the exception, and the stacktrace is only display in debug configuration. This issue is patched in symfony/http-foundation versions 4.4.5 and 5.0.5

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-03-17	0.06%	0.27%	+0.21%
2	2023-03-07	0.89%	0.06%	-0.83%
3	2022-04-01	—	0.89%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-03-17

0.06%

0.27%

+0.21%

2023-03-07

0.89%

0.06%

-0.83%

2022-04-01

—

0.89%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
4.6	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/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: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: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:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.	2.1	2.5	[email protected]
5.4	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/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: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: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.	2.8	2.5	[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]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

4.6

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/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: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: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:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N): Service keeps running; no real outage angle.

2.1

2.5

[email protected]

5.4

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/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: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: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.

2.8

2.5

[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]

OS Trackers for CVE-2020-5274

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2020-5274 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-2020-5274
`ubuntu`	medium	CVE-2020-5274 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-2020-5274

Affected software / configurations for CVE-2020-5274

Vendor	Product	Version	Raw CPE
sensiolabs	symfony	>= 4.4.0, < 4.4.4	cpe:2.3:a:sensiolabs:symfony::::::::
sensiolabs	symfony	>= 5.0.0, < 5.0.4	cpe:2.3:a:sensiolabs:symfony::::::::

References for CVE-2020-5274

URL	Tags
https://github.com/symfony/symfony/commit/629d21b800a15dc649fb0ae9ed7cd9211e7e45db	Patch Third Party Advisory
https://github.com/symfony/symfony/commit/cf80224589ac05402d4f72f5ddf80900ec94d5ad	Patch Third Party Advisory
https://github.com/symfony/symfony/security/advisories/GHSA-m884-279h-32v2	Third Party Advisory

URL

CVE-2020-5274 | Exceptions displayed in non-debug configurations in Symfony

Exploit prediction scoring system (EPSS) score for CVE-2020-5274

Common vulnerability scoring system (CVSS) metrics for CVE-2020-5274

Weakness enumeration for CVE-2020-5274

GitHub Security Advisory for CVE-2020-5274

OS Trackers for CVE-2020-5274

Affected software / configurations for CVE-2020-5274

References for CVE-2020-5274