CVE-2026-73522 in Open1722
Summary
by MITRE • 08/17/2026
COVESA Open1722 through 0.9.2 contains a stack buffer overflow vulnerability that allows unauthenticated remote attackers to write past the end of a fixed 15-slot stack array by sending a crafted UDP datagram containing more than 15 ACF-CAN messages. The avtp_to_can() function increments its write index without bounding it against the caller-supplied array size, and because the listener accepts datagrams from any sender matching a hardcoded unauthenticated stream ID transmitted in plaintext, attackers can corrupt adjacent stack memory to achieve arbitrary code execution or denial of service.
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Analysis
by VulDB Data Team • 08/17/2026
The vulnerability identified within COVESA Open1722 versions through 0.9.2 represents a critical security flaw rooted in improper input validation and lack of bounds checking during the processing of automotive communication protocols. Specifically, this is a stack-based buffer overflow that occurs when handling UDP datagrams containing Advanced Connection Framework Controller (ACF) CAN messages. The core technical failure lies within the avtp_to_can() function, which is responsible for translating Audio Video Transport Protocol data into CAN bus formats. This function accepts an array size parameter supplied by the caller but fails to validate this value against the actual allocated stack memory space before proceeding with write operations. Consequently, if a crafted UDP datagram contains more than fifteen ACF-CAN messages, the internal index used to track writes is incremented without being bounded by the fixed capacity of the underlying stack array, which consists of only fifteen slots. This architectural oversight allows an attacker to push data beyond the allocated memory boundaries, leading to corruption of adjacent stack frames and potentially overwriting critical control data such as return addresses or function pointers.
From a threat modeling perspective, this vulnerability is particularly severe due to its remote exploitable nature combined with a lack of authentication requirements. The listener component associated with this functionality accepts datagrams from any sender that matches a hardcoded unauthenticated stream ID transmitted in plaintext. This design choice effectively removes the barrier for initial access, allowing any network actor on the same broadcast domain or reachable via UDP to trigger the vulnerability without needing valid credentials. By sending a specifically crafted payload exceeding the fifteen-message threshold, an attacker can achieve arbitrary code execution by manipulating the stack memory layout to redirect program flow to malicious shellcode, or cause a denial of service through segmentation faults and application crashes. This aligns with CWE-121, which classifies stack-based buffer overflows as a primary category of memory corruption vulnerabilities that lead to unpredictable system behavior and potential full compromise.
The operational impact of this flaw extends beyond simple application instability. In the context of automotive networks where COVESA standards are often deployed, such as in infotainment systems or telematics units, compromising these components can provide an attacker with a foothold within the vehicle's internal network architecture. Once arbitrary code execution is achieved on a connected head unit or gateway device, lateral movement to other critical electronic control units becomes feasible. This scenario maps directly to MITRE ATT&CK techniques involving remote service exploitation and potential privilege escalation if the vulnerable process runs with elevated system privileges. The plaintext transmission of stream IDs further exacerbates the risk by facilitating reconnaissance, allowing attackers to easily identify valid targets for their crafted payloads without needing to decrypt or reverse-engineer communication channels first.
Mitigation strategies must address both the immediate code defect and broader architectural weaknesses. Developers should immediately patch the avtp_to-can() function to enforce strict bounds checking on all array write operations, ensuring that the number of processed messages never exceeds the predefined limit of fifteen slots regardless of caller-supplied parameters. Input validation logic must be implemented at the entry point of datagram processing to reject payloads with excessive message counts before they reach vulnerable functions. Furthermore, reliance on hardcoded unauthenticated stream IDs should be replaced with a robust authentication mechanism or encrypted channel verification to prevent unauthorized actors from targeting these services. Network segmentation and firewall rules restricting UDP traffic to trusted sources can also serve as effective compensating controls to limit the attack surface until software patches are deployed across all affected installations.