4.8 MEDIUM
- 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): Low (L)
- 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): Low (L)
- 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 TXT/SRV record parsing (unvalidated `rdlength`)
Zephyr's DNS resolver (subsys/net/lib/dns) parses resource records from DNS responses in dns_unpack_answer(), which validated only the fixed RR header (type, class, TTL, rdlength) and accepted any attacker-declared rdlength, including one extending past the end of the received datagram. The TXT and SRV consumers in dns_validate_record() (resolve.c) then read up to rdlength bytes (clamped only to a record-type maximum such as DNS_MAX_TEXT_SIZE, default 64, not to the packet) from the receive buffer via memcpy without their own bounds check, and pass the result to the application's resolve callback. A malicious or spoofed DNS server, an on-path attacker forging UDP DNS replies, or (with mDNS/LLMNR enabled) any LAN node can craft a truncated TXT or SRV response that causes an out-of-bounds read of adjacent receive-pool memory; the disclosed stale bytes (residual contents of prior DNS packets / uninitialized pool memory) are returned to the application as TXT/SRV record contents, an information leak, and may in some configurations cross the allocation boundary and fault, causing a denial of service. The read is bounded (~64 bytes for TXT, ~6 for SRV) and read-only (no write). The fix rejects any record whose declared rdata extends past dns_msg->msg_size at the single chokepoint in dns_unpack_answer(). Affected: v4.3.0 and v4.4.0.
References
-
Fix commit patch
-
GHSA-3jxq-xx8g-q8j2 exploit
Affected products
- <4.5.0
Matching in nixpkgs
pkgs.python312Packages.smoke-zephyr
None
pkgs.python313Packages.smoke-zephyr
Python utility collection
pkgs.python314Packages.smoke-zephyr
Python utility collection
pkgs.python312Packages.zephyr-python-api
None
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.python312Packages.zephyr-test-management
None
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>