Vulnerability in Yubico Yubihsm Connector
CVE-2021-28484
An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.015 (73.6th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 73.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000
Affected products
- Yubico Yubihsm Connector
- Fedoraproject Fedora — versions 34
Weakness classification (CWE)
References
- github.com/Yubico/yubihsm-connector/releases (Third Party Advisory)
- www.yubico.com/support/security-advisories/ysa-2021-02/ (Vendor Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
Frequently asked questions
- What is CVE-2021-28484?
- CVE-2021-28484 is a high-severity vulnerability in Yubico Yubihsm Connector, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 7.5/10. Published 2021-04-14.
- How severe is CVE-2021-28484?
- High severity. CVSS v3 base score is 7.5 out of 10.