CVE-2015-5600

HIGHCVSS 8.1/10EPSS 9.30%

Last modified

CVE-2015-5600 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processing of keyboard-interactive devices within a single connection, which makes it easier for remote attackers to conduct brute-force attacks or cause a denial of service (CPU consumption) via a long and duplicative list in the ssh -oKbdInteractiveDevices option, as demonstrated by a modified client that provides a different password for each pam element on this list.. EPSS estimates a 9.30% chance of exploitation in the next 30 days.

Description

The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processing of keyboard-interactive devices within a single connection, which makes it easier for remote attackers to conduct brute-force attacks or cause a denial of service (CPU consumption) via a long and duplicative list in the ssh -oKbdInteractiveDevices option, as demonstrated by a modified client that provides a different password for each pam element on this list.

Metrics

CVSS 3.1
8.1/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
9.30%

94.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
OpenbsdOpenssh<= 6.9

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2015-5600?
The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processing of keyboard-interactive devices within a single connection, which makes it easier for remote attackers to conduct brute-force attacks or cause a denial of service (CPU consumption) via a long and duplicative list in the ssh -oKbdInteractiveDevices option, as demonstrated by a modified client that provides a different password for each pam element on this list.
How severe is CVE-2015-5600?
CVE-2015-5600 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 9.30% probability of exploitation in the next 30 days.
How do I fix CVE-2015-5600?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2015-5600?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST