CVE-2026-55273 in Android
Summary
by MITRE • 09/08/2026
In AppendCommentLine of AnnotationProcessor.cpp, there is a possible supply chain risk due to improper input validation. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability identified in the AppendCommentLine function within AnnotationProcessor.cpp represents a critical flaw rooted in insufficient input validation, which directly facilitates supply chain risks and potential local privilege escalation. This specific code path appears to handle annotations or metadata comments, likely during a build process or source file processing stage where external inputs are integrated into project artifacts. The core technical issue lies in the failure to rigorously sanitize or validate user-supplied data before it is processed by the application logic. In software development pipelines, such functions often parse text-based configurations or embedded scripts; when input validation is lax, an attacker can inject malicious payloads that bypass expected parsing rules. This lack of sanitization allows for arbitrary code execution contexts within the scope of the running process, which frequently operates with elevated privileges to write files, modify system states, or interact with sensitive build tools.
From a supply chain perspective, this vulnerability poses a severe threat because it can be exploited during automated builds or continuous integration workflows where untrusted third-party libraries or user-generated content are processed. An adversary could manipulate the input data to execute arbitrary commands on the host machine without requiring additional execution privileges from the attacker's current context. This characteristic aligns with CWE-20, Improper Input Validation, as the system fails to verify that incoming data conforms to expected formats and constraints before processing. The absence of user interaction for exploitation further exacerbates the risk, allowing remote attackers or malicious scripts within a compromised repository to trigger this flaw automatically during routine operations such as compiling code or generating documentation.
The operational impact of this vulnerability extends beyond simple local privilege escalation; it undermines the integrity of the entire software delivery pipeline. If an attacker successfully exploits this flaw, they can achieve arbitrary command execution with the privileges of the build service account, which often possesses broad access to source repositories, deployment targets, and internal networks. This scenario is consistent with ATT&CK technique T1059, Command and Scripting Interpreter, where attackers leverage built-in system tools or scripts to execute malicious actions. Furthermore, it relates to ATT&CK tactic TA0004, Privilege Escalation, as the attacker gains higher-level access than initially possessed by leveraging the application's existing permissions. The supply chain risk is amplified because compromised build artifacts can propagate this vulnerability downstream to all consumers of the software, effectively poisoning the distribution channel.
Mitigation strategies must focus on implementing strict input validation and sanitization protocols within the AnnotationProcessor.cpp module. Developers should enforce allow-listing for acceptable characters in comment fields rather than relying solely on block-lists, which are prone to bypass through encoding variations or edge cases. Additionally, applying the principle of least privilege is essential; the process executing AppendCommentLine should run with minimal necessary permissions, limiting the potential damage if exploitation occurs. Implementing sandboxed environments for processing untrusted annotations can also isolate any malicious activity from critical system resources. Regular security audits and static analysis tools configured to detect CWE-20 patterns in C++ codebases are recommended to identify similar flaws early in the development lifecycle. Finally, integrating supply chain security measures such as signed commits and verified dependencies helps ensure that only trusted inputs reach this vulnerable function, thereby reducing the attack surface for injection-based exploits.