CVE-2021-3311

An issue was discovered in October through build 471. It reactivates an old session ID (which had been invalid after a logout) once a new login occurs. NOTE: this violates the intended Auth/Manager.php authentication behavior but, admittedly, is only relevant if an old session ID is known to an attacker.

An issue was discovered in October through build 471. It reactivates an old session ID (which had been invalid after a logout) once a new login occurs. NOTE: this violates the intended Auth/Manager.php authentication behavior but, admittedly, is only relevant if an old session ID is known to an attacker.

An issue was discovered in October through build 471. It reactivates an old session ID (which had been invalid after a logout) once a new login occurs. NOTE: this violates the intended Auth/Manager.php authentication behavior but, admittedly, is only relevant if an old session ID is known to an attacker.

Impact

When logging out, the session ID was not invalidated. This is not a problem while the user is logged out, but as soon as the user logs back in the old session ID would be valid again; which means that anyone that gained access to the old session cookie would be able to act as the logged in user. This is not a major concern for the majority of cases, since it requires a malicious party gaining access to the session cookie in the first place, but nevertheless has been fixed.

Patches

Issue has been patched in Build 472 (v1.0.472) and v1.1.2.

Workarounds

Apply https://github.com/octobercms/library/commit/642f597489e6f644d4bd9a0c267e864cabead024 to your installation manually if unable to upgrade to Build 472 or v1.1.2.

References

• Reported by Anisio (Brazilian Information Security Analyst)
• http://cve.circl.lu/cve/CVE-2021-3311

For more information

If you have any questions or comments about this advisory:

• Email us at [email protected]

Threat assessment:

<img width="699" alt="Screen Shot 2021-02-07 at 11 50 35 PM" src="https://user-images.githubusercontent.com/7253840/107180881-51eaf000-699f-11eb-8828-333128faf2a6.png">

An issue was discovered in October through build 471. It reactivates an old session ID (which had been invalid after a logout) once a new login occurs. NOTE: this violates the intended Auth/Manager.php authentication behavior but, admittedly, is only relevant if an old session ID is known to an attacker.

Impact

When logging out, the session ID was not invalidated. This is not a problem while the user is logged out, but as soon as the user logs back in the old session ID would be valid again; which means that anyone that gained access to the old session cookie would be able to act as the logged in user. This is not a major concern for the majority of cases, since it requires a malicious party gaining access to the session cookie in the first place, but nevertheless has been fixed.

Patches

Issue has been patched in Build 472 (v1.0.472) and v1.1.2.

Workarounds

Apply https://github.com/octobercms/library/commit/642f597489e6f644d4bd9a0c267e864cabead024 to your installation manually if unable to upgrade to Build 472 or v1.1.2.

References

• Reported by Anisio (Brazilian Information Security Analyst)
• http://cve.circl.lu/cve/CVE-2021-3311

For more information

If you have any questions or comments about this advisory:

• Email us at [email protected]

Threat assessment:

<img width="699" alt="Screen Shot 2021-02-07 at 11 50 35 PM" src="https://user-images.githubusercontent.com/7253840/107180881-51eaf000-699f-11eb-8828-333128faf2a6.png">