CVE-2021-32693Network attack vector

Cross-firewall authentication via unscoped context listener

Published Jun 17, 2021 · Updated Aug 3, 2024

Improper authentication in Symfony Security HTTP 5.3.0 through 5.3.1 allows remote authenticated users to cross firewall boundaries. ContextListener marks the request with a shared Boolean and then persists the authenticated token without verifying that its session key matches the firewall that handled the request. Applications must define multiple firewalls with different providers; a user authenticated to one area is then treated as authenticated in another.

CVSS severity6.8
Medium
EPSS probability1.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Symfony Security HTTP 5.3.0 through 5.3.1 allows remote authenticated users to cross firewall boundaries. ContextListener marks the request with a shared Boolean and then persists the authenticated token without verifying that its session key matches the firewall that handled the request. Applications must define multiple firewalls with different providers; a user authenticated to one area is then treated as authenticated in another.

The record

CVE
CVE-2021-32693
Published
Jun 17, 2021
Updated
Aug 3, 2024
Vendor
Symfony
Product
Symfony
Classifications
CWE-287, T1078
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 17, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 5.3.0, < 5.3.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Symfony · Symfonyversion=>= 5.3.0, < 5.3.2

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
6.8GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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