Cyber Resilience

CVE-2023-46733

Auth Bypass in Sensiolabs Symfony 5.4.21 – 5.4.31

Published
10 November 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.0069 50th percentile
Risk Priority 53 floored blend · peak EPSS

Summary

CVE-2023-46733 is a medium-severity Session Fixation (CWE-384) vulnerability in Sensiolabs Symfony. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Steal Web Session Cookie (T1539); ranked at the 50th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Starting in versions 5.4.21 and 6.2.7 and prior to versions 5.4.31 and 6.3.8, `SessionStrategyListener` does not migrate the session after every successful login.…

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It does so only in case the logged in user changes by means of checking the user identifier. In some use cases, the user identifier doesn't change between the verification phase and the successful login, while the token itself changes from one type (partially-authenticated) to another (fully-authenticated). When this happens, the session id should be regenerated to prevent possible session fixations, which is not the case at the moment. As of versions 5.4.31 and 6.3.8, Symfony now checks the type of the token in addition to the user identifier before deciding whether the session id should be regenerated.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
T1550.004 Web Session Cookie Lateral Movement
Adversaries can use stolen session cookies to authenticate to web applications and services.
T1606 Forge Web Credentials Credential Access
Adversaries may forge credential materials that can be used to gain access to web applications or Internet services.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-45074Same product: Sensiolabs Symfony
CVE-2026-45063Same product: Sensiolabs Symfony
CVE-2026-45753Same product: Sensiolabs Symfony
CVE-2023-46735Same product: Sensiolabs Symfony
CVE-2026-45072Same product: Sensiolabs Symfony
CVE-2026-48761Same product: Sensiolabs Symfony
CVE-2026-45069Same product: Sensiolabs Symfony
CVE-2026-45071Same product: Sensiolabs Symfony
CVE-2026-48784Same product: Sensiolabs Symfony
CVE-2026-48489Same product: Sensiolabs Symfony

Affected Assets

sensiolabs
symfony
5.4.21 — 5.4.31 · 6.2.7 — 6.3.8

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V4.4.4
  • V7.6.2

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-384

Session termination after a set interval shortens the usable lifetime of a fixed session identifier, making successful exploitation of session fixation more difficult.

addresses: CWE-384

Re-authentication typically forces issuance of a new session, limiting the window for exploitation of a previously fixed session identifier.

addresses: CWE-384

Enforces proper session ID generation and binding, preventing fixation of a known session token.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 mostly match
prevents

Proper authentication processes must invalidate prior session identifiers to prevent fixation attacks.

PR.AA-01 partial match
prevents

Managing identities and credentials includes handling session identifiers as temporary credentials that must be invalidated on re-authentication.

PR.AA-04 partial match
prevents

Protecting and verifying identity assertions encompasses secure handling and regeneration of session tokens.

PR.PS-01 partial match
prevents

Configuration baselines can enforce session regeneration and timeout settings that block fixation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect session-fixation issues, yet the weakness absence does not replace comprehensive testing.

degrades

Access-control policy can mandate session invalidation on re-authentication, but does not prescribe the technical mechanism.

degrades

Identity-management procedures can require new session tokens after login, yet the control is broader than session handling.

degrades

Authentication-information rules can include session-token lifecycle requirements, but the control focuses on credential management.

prevents

Secure-SDLC requirement can embed session-fixation checks, but eliminating the weakness does not satisfy the full SDLC control.

prevents

Application-security requirements can specify session handling, yet the weakness fix alone does not meet the broader requirement.

References