HOMEVULNERABILITIESCVE-2021-41268
HIGH

CVE-2021-41268

CWE-384Published: November 24, 2021· Updated: Jun 17, 2026

8.8
CVSS v3.1

Official Description

Symfony/SecurityBundle is the security system for Symfony, a PHP framework for web and console applications and a set of reusable PHP components. Since the rework of the Remember me cookie in version 5.3.0, the cookie is not invalidated when the user changes their password. Attackers can therefore maintain their access to the account even if the password is changed as long as they have had the chance to login once and get a valid remember me cookie. Starting with version 5.3.12, Symfony makes the password part of the signature by default. In that way, when the password changes, then the cookie is not valid anymore.

NVD Source

Technical Analysis

CVE-2021-41268 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

sensiolabs1 product(s)
symfony
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
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Official Patches & Advisories

PATCHhttps://github.com/symfony/symfony/commit/36a808b857cd3240244f4b224452fb1e70dc6dfc
PATCHhttps://github.com/symfony/symfony/pull/44243
PATCHhttps://github.com/symfony/symfony/security/advisories/GHSA-qw36-p97w-vcqr
PATCHhttps://github.com/symfony/symfony/commit/36a808b857cd3240244f4b224452fb1e70dc6dfc
PATCHhttps://github.com/symfony/symfony/pull/44243
PATCHhttps://github.com/symfony/symfony/security/advisories/GHSA-qw36-p97w-vcqr
ADVISORYhttps://github.com/symfony/symfony/releases/tag/v5.3.12
ADVISORYhttps://github.com/symfony/symfony/releases/tag/v5.3.12

All References (8)

→
https://github.com/symfony/symfony/commit/36a808b857cd3240244f4b224452fb1e70dc6dfcPatch · Third Party Advisory
→
https://github.com/symfony/symfony/pull/44243Patch · Third Party Advisory
→
https://github.com/symfony/symfony/releases/tag/v5.3.12Release Notes · Third Party Advisory
→
https://github.com/symfony/symfony/security/advisories/GHSA-qw36-p97w-vcqrPatch · Third Party Advisory
→
https://github.com/symfony/symfony/commit/36a808b857cd3240244f4b224452fb1e70dc6dfcPatch · Third Party Advisory
→
https://github.com/symfony/symfony/pull/44243Patch · Third Party Advisory
→
https://github.com/symfony/symfony/releases/tag/v5.3.12Release Notes · Third Party Advisory
→
https://github.com/symfony/symfony/security/advisories/GHSA-qw36-p97w-vcqrPatch · Third Party Advisory

Quick Facts

CVE IDCVE-2021-41268
CVSS Score8.8 / 10
SeverityHIGH
WeaknessCWE-384
CISA KEVNo
Affected1 vendor(s)
PublishedNov 24, 2021

Related CVEs (CWE-384)

CVE-2021-20151
10.0
CVE-2024-11317
10.0
CVE-2025-28238
9.8
CVE-2025-28242
9.8
CVE-2022-40916
9.8
CVE-2025-45949
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-41268 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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