CVE-2021-3773
What it is
A flaw in netfilter could allow a network-connected attacker to infer openvpn connection endpoint information for further use in traditional network attacks.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 5.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 5.3% in the next 30 days (EPSS).
- Severity: 9.8 CRITICAL (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 5.3% · EPSS, next 30 days
- Weakness
- CWE-200 · Information exposure
- Record status
- Modified
Affected
- Linux Kernel < 5.14
- Linux Kernel < 5.15.15
- Fedoraproject Fedora 34
- Redhat Enterprise Linux 6.0
- Redhat Enterprise Linux 7.0
- Redhat Enterprise Linux 8.0
- Oracle Communications Cloud Native Core Binding Support Function 22.1.3
- Oracle Communications Cloud Native Core Network Exposure Function 22.1.1
Attack profile CVSS 3.1 · 9.8
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-3773.md and follow it. Check whether this project is affected by CVE-2021-3773. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://www.oracle.com/security-alerts/cpujul2022.html
- https://www.oracle.com/security-alerts/cpujul2022.html
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2004949
- https://citizenlab.ca/2024/07/vulnerabilities-in-vpns-paper-presented-at-the-privacy-enhancing-technologies-symposium-2024/
- https://www.oracle.com/security-alerts/cpujul2022.html
- https://bugzilla.redhat.com/show_bug.cgi?id=2004949
- https://citizenlab.ca/2024/07/vulnerabilities-in-vpns-paper-presented-at-the-privacy-enhancing-technologies-symposium-2024/
- https://security.netapp.com/advisory/ntap-20250328-0004/
- https://www.oracle.com/security-alerts/cpujul2022.html