CVE-2021-28484
An attacker can send 0, 1, or 2 bytes to trigger this.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.52%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.52% probability · 73th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-835
- Affected
- yubico/yubihsm connector · fedoraproject/fedora
- Source
- cve@mitre.org
References
- https://github.com/Yubico/yubihsm-connector/releasesThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/B7Q2KGXSPQEEONAWMFZRVH2TXWX3QPCQ/
- https://www.yubico.com/support/security-advisories/ysa-2021-02/Vendor Advisory
- https://github.com/Yubico/yubihsm-connector/releasesThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/B7Q2KGXSPQEEONAWMFZRVH2TXWX3QPCQ/
- https://www.yubico.com/support/security-advisories/ysa-2021-02/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.