Cyber Resilience

CVE-2021-3311

CriticalPublic PoC

Published: 05 February 2021

Published
05 February 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0152 81.7th percentile
Risk Priority 21 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-3311 is a critical-severity Insufficient Session Expiration (CWE-613) vulnerability in Octobercms October. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 18.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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…

more

if an old session ID is known to an attacker.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

octobercms
october
≤ 1.0.471

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-613

Locks the device (typically after inactivity) until re-authentication, addressing insufficient session expiration by preventing indefinite access.

addresses: CWE-613

Automatically terminating sessions after a defined period directly enforces session expiration, preventing indefinite session lifetimes that attackers can exploit.

addresses: CWE-613

Re-authentication after inactivity or time-based triggers prevents indefinite use of potentially hijacked or stale sessions.

addresses: CWE-613

Terminating sessions and network connections upon completion prevents insufficient session expiration.

addresses: CWE-613

Directly enforces termination of network sessions after inactivity or end-of-session, preventing indefinite session lifetime.

addresses: CWE-613

Consistent clocks across systems allow session expiration and timeout enforcement to function as intended in distributed environments.

addresses: CWE-613

When the non-persistent artifact is a session or connection, mandatory termination implements the missing expiration that CWE-613 describes.

addresses: CWE-613

Timed refresh of session-related information or on-demand generation plus deletion implements proper session expiration.

References