CVE-2020-15094 [High] | RCE in Httpclient

In Symfony before versions 4.4.13 and 5.1.5, the CachingHttpClient class from the HttpClient Symfony component relies on the HttpCache class to handle requests. HttpCache uses internal headers like X-Body-Eval and X-Body-File to control the restoration of cached responses. The class was initially written with surrogate caching and ESI support in mind (all HTTP calls come from a trusted backend in that scenario). But when used by CachingHttpClient and if an attacker can control the response for a request being made by the CachingHttpClient, remote code execution is possible. This has been fixed in versions 4.4.13 and 5.1.5.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-03-30	6.93%	2.25%	-4.68%
2	2025-03-29	2.25%	6.93%	+4.68%
3	2025-03-17	—	2.25%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-03-30

6.93%

2.25%

-4.68%

2025-03-29

2.25%

6.93%

+4.68%

2025-03-17

—

2.25%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
8.0	3.1	HIGH	`CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/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: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: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.	1.3	6.0	[email protected]
8.8	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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: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:H) Could take the service down hard or make it unusable for people who depend on it.	2.8	5.9	[email protected]
7.5	2.0	HIGH	`AV:N/AC:L/Au:N/C:P/I:P/A:P` 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:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	10.0	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

8.0

3.1

HIGH

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/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: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: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.

1.3

6.0

[email protected]

8.8

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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: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:H): Could take the service down hard or make it unusable for people who depend on it.

2.8

5.9

[email protected]

7.5

2.0

HIGH

AV:N/AC:L/Au:N/C:P/I:P/A:P 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:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

6.4

[email protected]

OS Trackers for CVE-2020-15094

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2020-15094 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-2020-15094
`ubuntu`	medium	CVE-2020-15094 medium priority: Ubuntu including 1 source packages (symfony), 9 status rows across 9 suites (bionic, focal, groovy, hirsute, impish, jammy, trusty, upstream, xenial): not-affected 5, ignored 2, DNE 1, released 1.	https://ubuntu.com/security/CVE-2020-15094

Affected software / configurations for CVE-2020-15094

Vendor	Product	Version	Raw CPE
sensiolabs	httpclient	>= 4.4.0, < 4.4.13	cpe:2.3:a:sensiolabs:httpclient::::::::
sensiolabs	httpclient	>= 5.1.0, < 5.1.5	cpe:2.3:a:sensiolabs:httpclient::::::::
sensiolabs	symfony	>= 4.4.0, < 4.4.13	cpe:2.3:a:sensiolabs:symfony::::::::
sensiolabs	symfony	>= 5.1.0, < 5.1.5	cpe:2.3:a:sensiolabs:symfony::::::::
fedoraproject	fedora	32	cpe:2.3:o:fedoraproject:fedora:32:::::::*
fedoraproject	fedora	33	cpe:2.3:o:fedoraproject:fedora:33:::::::*

References for CVE-2020-15094

URL	Tags
https://github.com/symfony/symfony/commit/d9910e0b33a2e0f993abff41c6fbc86951b66d78	Patch Third Party Advisory
https://github.com/symfony/symfony/security/advisories/GHSA-754h-5r27-7x3r	Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HNGUWOEETOFVH4PN3I3YO4QZHQ4AUKF3/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VAQJXAKWPMWB7OL6QPG2ZSEQZYYPU5RC/
https://packagist.org/packages/symfony/http-kernel	Product Third Party Advisory
https://packagist.org/packages/symfony/symfony	Product Third Party Advisory

URL

CVE-2020-15094 | RCE in Symfony

Exploit prediction scoring system (EPSS) score for CVE-2020-15094

Common vulnerability scoring system (CVSS) metrics for CVE-2020-15094

Weakness enumeration for CVE-2020-15094

GitHub Security Advisory for CVE-2020-15094

OS Trackers for CVE-2020-15094

Affected software / configurations for CVE-2020-15094

References for CVE-2020-15094