CVE-2023-30312
An issue discovered in OpenWrt 18.06, 19.07, 21.02, 22.03, and beyond allows off-path attackers to hijack TCP sessions, which could lead to a denial of service, impersonating the client to the server (e.g., for access to files over FTP), and impersonating the server to the client (e.g., to deliver false information from a finance website). This occurs because nf_conntrack_tcp_no_window_check is true by default.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
An issue discovered in OpenWrt 18.06, 19.07, 21.02, 22.03, and beyond allows off-path attackers to hijack TCP sessions, which could lead to a denial of service, impersonating the client to the server (e.g., for access to files over FTP), and impersonating the server to the client (e.g., to deliver false information from a finance website). This occurs because nf_conntrack_tcp_no_window_check is true by default.
- Record
CVE-2023-30312- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H - Weakness
- CWE-203
- Updated
- 2026-11-02
EUVDEUVD-2023-34735
An issue discovered in OpenWrt 18.06, 19.07, 21.02, 22.03, and beyond allows off-path attackers to hijack TCP sessions, which could lead to a denial of service, impersonating the client to the server (e.g., for access to files over FTP), and impersonating the server to the client (e.g., to deliver false information from a finance website). This occurs because nf_conntrack_tcp_no_window_check is true by default.
- Record
EUVD-2023-34735- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H - Updated
- 2026-11-03
NVD
An issue discovered in OpenWrt 18.06, 19.07, 21.02, 22.03, and beyond allows off-path attackers to hijack TCP sessions, which could lead to a denial of service, impersonating the client to the server (e.g., for access to files over FTP), and impersonating the server to the client (e.g., to deliver false information from a finance website). This occurs because nf_conntrack_tcp_no_window_check is true by default.
- Record
CVE-2023-30312- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H - Weakness
- CWE-203
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-30312 is a high vulnerability (CVSS 7.3), published May 28, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.29%, the 22nd percentile. No source names a fixed version.