CVE-2021-27217

Public Exploit

Description

An issue was discovered in the _send_secure_msg() function of Yubico yubihsm-shell through 2.0.3. The function does not correctly validate the embedded length field of an authenticated message received from the device. Out-of-bounds reads performed by aes_remove_padding() can crash the running process, depending on the memory layout. This could be used by an attacker to cause a client-side denial of service. The yubihsm-shell project is included in the YubiHSM 2 SDK product.

Category

4.4
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.61%
Vendor Advisory yubico.com
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://github.com/Yubico/yubihsm-shell/releases third party advisory release notes
https://www.yubico.com/support/security-advisories/ysa-2021-01/ vendor advisory
https://blog.inhq.net/posts/yubico-libyubihsm-vuln2 third party advisory exploit

Frequently Asked Questions

What is the severity of CVE-2021-27217?
CVE-2021-27217 has been scored as a medium severity vulnerability.
How to fix CVE-2021-27217?
To fix CVE-2021-27217, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-27217 being actively exploited in the wild?
It is possible that CVE-2021-27217 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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