CVE-2021-28041
ssh-agent in OpenSSH before 8.5 has a double free that may be relevant in a few less-common scenarios, such as unconstrained agent-socket access on a legacy operating…
Published Mar 5, 2021 · corrected/updated Oct 14, 2026 · openbsd openssh · evidence confidence high
ssh-agent in OpenSSH before 8.5 has a double free that may be relevant in a few less-common scenarios, such as unconstrained agent-socket access on a legacy operating system, or the forwarding of an agent to an attacker-controlled host.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2021-28041 is a high public vulnerability record for openbsd openssh. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether openbsd openssh is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: fedoraproject/fedora (33); fedoraproject/fedora (34); netapp/cloud backup; netapp/hci compute node firmware. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 7.1, EPSS 3.5%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-415. Sources contributing to this record: cve_org, epss, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Mar 5, 2021 · NIST NVD
Detected
ssh-agent in OpenSSH before 8.5 has a double free that may be relevant in a few less-common scenarios, such as unconstrained agent-socket access on a legacy operating system, or the forwarding of an agent to an attacker-controlled host.
Oct 14, 2026 · NIST NVD
Updated
ssh-agent in OpenSSH before 8.5 has a double free that may be relevant in a few less-common scenarios, such as unconstrained agent-socket access on a legacy operating system, or the forwarding of an agent to an attacker-controlled host.
Affected
- cpe fedoraproject/fedora33
- cpe fedoraproject/fedora34
- cpe netapp/cloud backupversion unspecified
- cpe netapp/hci compute node firmwareversion unspecified
- cpe netapp/hci management nodeversion unspecified
- cpe netapp/hci storage node firmwareversion unspecified
- cpe netapp/solidfireversion unspecified
- cpe openbsd/opensshversion unspecified
- cpe oracle/communications offline mediation controller12.0.0.3.0
Sources
- CVE.orgVulnerability recordCVE-2021-28041
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2021-28041
30-day exploitation probability 3.5%
first.org - NIST NVDVulnerability recordCVE-2021-28041
ssh-agent in OpenSSH before 8.5 has a double free that may be relevant in a few less-common scenarios, such as unconstrained agent-socket access on a legacy operating system, or the forwarding of an agent to an attacker-controlled host.
nvd.nist.gov