How severe is CVE-2013-3656?

CVE-2013-3656 has a CVSS 2.0 base score of 5.8, rated medium severity.

Is CVE-2013-3656 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2013-3656?

CVE-2013-3656 affects Cybozu Cybozu Office. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2013-3656?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2013-3656 published?

CVE-2013-3656 was published on 2013-07-20 and last updated on 2026-06-16.

CVE-2013-3656

CVE-2013-3656 is a medium-severity vulnerability in Cybozu Cybozu Office with a CVSS 2.0 base score of 5.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: Medium (CVSS 2.0 base score 5.8)
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Cybozu Cybozu Office
Published: 2013-07-20
Last modified: 2026-06-16

Description

Cybozu Office 9.1.0 and earlier does not properly manage sessions, which allows remote attackers to bypass authentication by leveraging knowledge of a login URL.

Frequently asked questions

What is CVE-2013-3656?: Cybozu Office 9.1.0 and earlier does not properly manage sessions, which allows remote attackers to bypass authentication by leveraging knowledge of a login URL.
How severe is CVE-2013-3656?: CVE-2013-3656 has a CVSS 2.0 base score of 5.8, rated medium severity.
Is CVE-2013-3656 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2013-3656?: CVE-2013-3656 affects Cybozu Cybozu Office. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2013-3656?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2013-3656 published?: CVE-2013-3656 was published on 2013-07-20 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:cybozu:cybozu_office:*:*:*:*:*:*:*:*

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Other CWE-287 (Improper Authentication) vulnerabilities

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CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
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Browse all CWE-287 (Improper Authentication) vulnerabilities →