OpenWrt is a Linux operating system targeting embedded devices. Before v25.12.5, an integer underflow in handle_send_a() of the Emergency Access Daemon allows any unauthenticated attacker on the local network to crash the daemon by sending a single crafted UDP packet. The message length underflows before a bounds check and is then passed to memcpy as a very large size.
This issue is fixed v25.12.5.
Attack Parameters
Attack Vector
Adjacent
Requires local network access
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products 1
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Openwrt Openwrt
cpe:2.3:o:openwrt:openwrt:*:*:*:*:*:*:*:*
|
— |
25.12.5
|
References 3
https://github.com/openwrt/openwrt/commit/63c0767f3d02f7b10b0f0b5293366bd059a08…
security-advisories@github.com
https://github.com/openwrt/openwrt/releases/tag/v25.12.5
security-advisories@github.com
https://github.com/openwrt/openwrt/security/advisories/GHSA-9558-77jp-g3fw
security-advisories@github.com