CVE-2020-17360 in Avian
Summary
by MITRE
** UNSUPPORTED WHEN ASSIGNED ** An issue was discovered in ReadyTalk Avian 1.2.0. The vm::arrayCopy method defined in classpath-common.h contains multiple boundary checks that are performed to prevent out-of-bounds memory read/write. However, two of these boundary checks contain an integer overflow that leads to a bypass of these checks, and out-of-bounds read/write. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
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Analysis
by VulDB Data Team • 05/05/2025
The vulnerability identified as CVE-2020-17360 resides within ReadyTalk Avian 1.2.0, a Java Virtual Machine implementation that operates on the Android platform. This particular flaw manifests in the vm::arrayCopy method located within the classpath-common.h file, representing a critical security weakness that undermines the integrity of memory operations. The vulnerability is classified under CWE-191, Integer Underflow (Wrap or Wraparound), which specifically addresses scenarios where integer arithmetic operations produce results that fall outside the expected range, creating exploitable conditions.
The technical implementation of this vulnerability stems from inadequate boundary validation mechanisms within the vm::arrayCopy method. While the code includes multiple boundary checks designed to prevent out-of-bounds memory access, two of these protective measures contain integer overflow conditions that allow attackers to bypass the intended security controls. When integer overflow occurs in these specific boundary checks, the validation logic fails to properly detect invalid memory operations, enabling unauthorized read and write access beyond the allocated array boundaries. This issue directly aligns with ATT&CK technique T1059.007, which involves the use of scripting languages to execute malicious code, as the vulnerability can be exploited through crafted array operations that leverage the overflow conditions.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates opportunities for privilege escalation and potential remote code execution within the constrained environment of the Avian JVM. Attackers could exploit these integer overflow conditions to manipulate memory layout and potentially execute arbitrary code with the privileges of the running application. The vulnerability's classification as a memory safety issue places it within the broader category of memory corruption vulnerabilities that have historically been exploited for system compromise. Organizations utilizing unsupported software versions face heightened risk exposure since the original vendor has ceased maintenance and security updates, leaving these systems vulnerable to exploitation without remediation options.
Mitigation strategies for this vulnerability are limited due to the unsupported nature of the affected product, but organizations should consider immediate removal of the vulnerable software from production environments. The recommended approach involves implementing network segmentation and access controls to limit exposure, while also planning for migration to supported alternatives. Security teams should monitor for any signs of exploitation attempts and consider implementing application whitelisting policies to prevent execution of potentially malicious code. Additionally, organizations should conduct comprehensive vulnerability assessments to identify any other instances of unsupported software within their infrastructure, as similar vulnerabilities may exist in other legacy systems. The ATT&CK framework suggests implementing defensive measures such as process monitoring and anomaly detection to identify potential exploitation attempts that leverage integer overflow conditions in memory management functions.