How severe is CVE-2015-6563?

CVE-2015-6563 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2015-6563 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-6563?

CVE-2015-6563 primarily affects Openbsd Openssh. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-6563?

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

When was CVE-2015-6563 published?

CVE-2015-6563 was published on 2015-08-24 and last updated on 2026-06-17.

CVE-2015-6563

CVE-2015-6563 is a medium-severity vulnerability in Openbsd Openssh with a CVSS 3.x base score of 6.4. 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-20.

Key facts

Severity: Medium (CVSS 3.x base score 6.4)
CVSS v2: 1.9
EPSS exploit prediction: 0% (30th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Openbsd Openssh
Published: 2015-08-24
Last modified: 2026-06-17

Description

The monitor component in sshd in OpenSSH before 7.0 on non-OpenBSD platforms accepts extraneous username data in MONITOR_REQ_PAM_INIT_CTX requests, which allows local users to conduct impersonation attacks by leveraging any SSH login access in conjunction with control of the sshd uid to send a crafted MONITOR_REQ_PWNAM request, related to monitor.c and monitor_wrap.c.

Frequently asked questions

What is CVE-2015-6563?: The monitor component in sshd in OpenSSH before 7.0 on non-OpenBSD platforms accepts extraneous username data in MONITOR_REQ_PAM_INIT_CTX requests, which allows local users to conduct impersonation attacks by leveraging any SSH login access in conjunction with control of the sshd uid to send a crafted MONITOR_REQ_PWNAM request, related to monitor.c and monitor_wrap.c.
How severe is CVE-2015-6563?: CVE-2015-6563 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2015-6563 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-6563?: CVE-2015-6563 primarily affects Openbsd Openssh. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-6563?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2015-6563 published?: CVE-2015-6563 was published on 2015-08-24 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:openbsd:openssh:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

122.114.69.235 (ipv4-addr)
92.47.46.174 (ipv4-addr)
76.12.128.249 (ipv4-addr)
64.53.7.231 (ipv4-addr)
62.182.118.138 (ipv4-addr)
61.76.136.25 (ipv4-addr)
213.135.175.76 (ipv4-addr)
187.237.47.214 (ipv4-addr)