3.7 LOW
- CVSS version (CVSS): 3.1
- Attack Vector (AV): Network (N)
- Attack Complexity (AC): High (H)
- Privileges Required (PR): None (N)
- User Interaction (UI): None (N)
- Scope (S): Unchanged (U)
- Confidentiality (C): None (N)
- Integrity (I): None (N)
- Availability (A): Low (L)
- Modified Attack Vector (MAV): Network (N)
- Modified Attack Complexity (MAC): High (H)
- Modified Privileges Required (MPR): None (N)
- Modified User Interaction (MUI): None (N)
- Modified Confidentiality (MC): None (N)
- Modified Scope (MS): Unchanged (U)
- Modified Integrity (MI): None (N)
- Modified Availability (MA): Low (L)
Activity log
- Created suggestion
Out-of-bounds read in Zephyr DNS resolver mDNS suffix check (memcmp past string NUL)
Zephyr's DNS resolver detects mDNS (.local) queries in dns_resolve_name_internal() (subsys/net/lib/dns/resolve.c) with memcmp(strrchr(query, '.'), ".local", 7), which always reads a fixed 7 bytes from the suffix pointer. When the resolved hostname's final label is shorter than 7 bytes (e.g. names ending in .org, .com, .net, .io, or a trailing dot), the comparison reads 1-2 bytes past the string's NUL terminator. The hostname (query) is the caller-supplied name passed through the standard getaddrinfo()/dns_get_addr_info()/dns_resolve_name() path and is influenceable by operators or remote inputs (server names from configuration, parsed URLs, or app-facing interfaces). On a tightly-sized buffer with no slack (for example a userspace getaddrinfo call where the hostname is copied with k_usermode_string_alloc_copy to exactly strlen+1 bytes), the over-read crosses the allocation boundary; if that boundary is unmapped (guard page, memory-domain boundary under MPU, or an address sanitizer) the over-read faults, causing a denial of service. The over-read bytes are never returned, so there is no information disclosure. The flaw is compiled only when CONFIG_MDNS_RESOLVER is enabled, exists since v1.10.0, and is fixed by replacing the fixed-length memcmp with a NUL-safe strcmp(ptr, ".local").
References
Affected products
- <4.5.0
Matching in nixpkgs
pkgs.python313Packages.smoke-zephyr
Python utility collection
pkgs.python314Packages.smoke-zephyr
Python utility collection
pkgs.python313Packages.zephyr-python-api
Set of wrappers for Zephyr Scale (TM4J) REST API
pkgs.python314Packages.zephyr-python-api
Set of wrappers for Zephyr Scale (TM4J) REST API
pkgs.python313Packages.zephyr-test-management
Wrappers for both Zephyr Scale and Zephyr Squad (TM4J) REST APIs
Package maintainers
-
@fabaff Fabian Affolter <mail@fabian-affolter.ch>
-
@Steinhagen Viorel-Cătălin Răpițeanu <rapiteanu.catalin@gmail.com>