How severe is CVE-2007-2243?

CVE-2007-2243 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2007-2243 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2007-2243?

CVE-2007-2243 primarily affects Openbsd Openssh. In total, 62 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2007-2243?

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

When was CVE-2007-2243 published?

CVE-2007-2243 was published on 2007-04-25 and last updated on 2026-06-16.

CVE-2007-2243

CVE-2007-2243 is a medium-severity vulnerability in Openbsd Openssh with a CVSS 2.0 base score of 5.0. 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 5.0)
EPSS exploit prediction: 2% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Openbsd Openssh
Published: 2007-04-25
Last modified: 2026-06-16

Description

OpenSSH 4.6 and earlier, when ChallengeResponseAuthentication is enabled, allows remote attackers to determine the existence of user accounts by attempting to authenticate via S/KEY, which displays a different response if the user account exists, a similar issue to CVE-2001-1483.

Frequently asked questions

What is CVE-2007-2243?: OpenSSH 4.6 and earlier, when ChallengeResponseAuthentication is enabled, allows remote attackers to determine the existence of user accounts by attempting to authenticate via S/KEY, which displays a different response if the user account exists, a similar issue to CVE-2001-1483.
How severe is CVE-2007-2243?: CVE-2007-2243 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2007-2243 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2007-2243?: CVE-2007-2243 primarily affects Openbsd Openssh. In total, 62 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2007-2243?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2007-2243 published?: CVE-2007-2243 was published on 2007-04-25 and last updated on 2026-06-16.

References

Affected products (62)

cpe:2.3:a:openbsd:openssh:1.2:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:1.2.1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:1.2.2:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:1.2.3:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:1.2.27:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.1.1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.2:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.3:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.5:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.5.1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.5.2:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.9:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.9.9:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.9.9p2:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.9p1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:2.9p2:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.0:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.0.1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.0.1p1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.0.2:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.0.2p1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.0p1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.1p1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.2:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.2.2:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.2.2p1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.2.3p1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.3:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.3p1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.4:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.4p1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.5:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.5p1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.6:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.6.1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.6.1p1:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.6.1p2:*:*:*:*:*:*:*
cpe:2.3:a:openbsd:openssh:3.7:*:*:*:*:*:*:*

More vulnerabilities in Openbsd Openssh

CVE-2003-0786 — Critical (CVSS 10.0): The SSH1 PAM challenge response authentication in OpenSSH 3.7.1 and 3.7.1p1, when Privilege Separation is disabled,…
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CVE-2002-0640 — Critical (CVSS 10.0): Buffer overflow in sshd in OpenSSH 2.3.1 through 3.3 may allow remote attackers to execute arbitrary code via a large…
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CVE-2000-0999 — Critical (CVSS 10.0): Format string vulnerabilities in OpenBSD ssh program (and possibly other BSD-based operating systems) allow attackers…
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All CVEs affecting Openbsd Openssh →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

Browse all CWE-287 (Improper Authentication) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

60.166.8.174 (ipv4-addr)
60.166.31.198 (ipv4-addr)
112.31.93.229 (ipv4-addr)
61.191.145.123 (ipv4-addr)
60.29.128.122 (ipv4-addr)
223.82.97.51 (ipv4-addr)
183.6.115.88 (ipv4-addr)
175.203.199.118 (ipv4-addr)