CVE-2021-3773: A flaw in netfilter could allow a network-connected attacker to infer openvpn connection endpoint information for further use in traditional

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• fedoraproject fedora34
• linux linux kernel5.15 and later · before 5.15.15
• linux linux kernelbefore 5.14
• oracle communications cloud native core binding support function22.1.3
• oracle communications cloud native core network exposure function22.1.1
• oracle communications cloud native core policy22.2.0
• redhat enterprise linux6.0
• redhat enterprise linux7.0
• redhat enterprise linux8.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

• n/a kernel

  • kernel 5.14.0-49.el9, kernel 5.15.15-100.fc34, kernel 5.15.15-200.fc35affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Other highest-scoring records for the same primary product.

• CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
  90Now
• CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
  89Now
• CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
  85Now

Published before and after this one in the same product

• ← EarlierCVE-2021-3753Feb 16, 2022 · A race problem was seen in the vt_k_ioctl in drivers/tty/vt/vt_ioctl.c in the Linux kernel, which may cause an out of bounds read in vt as t
  18Monitor
• ← EarlierCVE-2021-3760Feb 16, 2022 · A flaw was found in the Linux kernel.
  31Monitor
• Later →CVE-2022-25258Feb 16, 2022 · An issue was discovered in drivers/usb/gadget/composite.c in the Linux kernel before 5.16.10.
  18Monitor

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

The extension requests broader permissions than its function needs and sends the data it collects out for purposes beyond its stated function.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1{2  "permissions": ["tabs", "<all_urls>"],3  "background": { "service_worker": "analytics.js" }4}

1{2  "permissions": ["activeTab"],3  "host_permissions": ["https://yildiz.example/*"]4}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.