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PatchSiren cyber security CVE debrief

CVE-2017-5539 B2evolution CVE debrief

CVE-2017-5539 is a critical directory traversal patch bypass in b2evolution 6.8.4-stable. An unauthenticated remote attacker can use `..\/` to bypass the filter and potentially read, delete, or probe files on the server.

Vendor
B2evolution
Product
Unknown
CVSS
CRITICAL 9.1
CISA KEV
Not listed in stored evidence
Original CVE published
2017-01-23
Original CVE updated
2026-05-13
Advisory published
2017-01-23
Advisory updated
2026-05-13

Who should care

Administrators, developers, and security teams running b2evolution 6.8.4-stable, especially on internet-facing systems or any deployment that stores sensitive files on the server.

Technical summary

NVD classifies this issue as CWE-22 and maps it to b2evolution 6.8.4 as vulnerable. The supplied description says the fix for CVE-2017-5480 was bypassed with `..\/`, allowing file read, file deletion, and file-existence checks. The CVSS 3.0 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N) indicates network-reachable exploitation with no privileges or user interaction required, and high confidentiality and integrity impact.

Defensive priority

Critical — prioritize immediate remediation for any exposed b2evolution 6.8.4-stable instance.

Recommended defensive actions

  • Upgrade b2evolution to the vendor-referenced fixed release, 6.8.5.
  • Confirm whether any b2evolution 6.8.4-stable instances are deployed and treat them as affected until patched.
  • Review logs and file-system activity for signs of unexpected file access, deletion, or path traversal attempts.
  • Re-test application path handling after patching to confirm the traversal bypass is no longer possible.

Evidence notes

The supplied NVD record was published on 2017-01-23 and last modified on 2026-05-13. It references a vendor advisory for 6.8.5, a related GitHub fix commit, and an issue tracker entry. The CVSS vector and CWE-22 classification come from the official NVD data, and the vulnerability scope is limited here to the supplied b2evolution 6.8.4-stable reference.

Sources and references

Verified primary and authoritative sources

  • CVE-2017-5539 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2017-5539

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2017-5539 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2017-5539

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.