CVE-2008-5352 in SDKJDK
Summary
by MITRE
Integer overflow in the JAR unpacking utility (unpack200) in the unpack library (unpack.dll) in Java Runtime Environment (JRE) for Sun JDK and JRE 6 Update 10 and earlier, and JDK and JRE 5.0 Update 16 and earlier, allows untrusted applications and applets to gain privileges via a Pack200 compressed JAR file that triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 08/21/2019
The vulnerability described in CVE-2008-5352 represents a critical integer overflow flaw within the Java Runtime Environment's Pack200 decompression functionality. This issue affects the unpack200 utility within the unpack.dll library, which is responsible for handling Pack200 compressed JAR files. The vulnerability specifically targets Java versions 6 Update 10 and earlier, as well as JDK and JRE 5.0 Update 16 and earlier, making it a widespread concern across multiple Java runtime versions. The flaw occurs during the unpacking process when processing maliciously crafted Pack200 compressed files that contain malformed integer values.
The technical implementation of this vulnerability stems from improper input validation within the JAR unpacking utility. When the unpack200 tool processes a Pack200 compressed file, it performs calculations to determine buffer sizes needed for decompression operations. An attacker can craft a specially designed Pack200 file that contains integer values large enough to cause arithmetic overflow when used in buffer size calculations. This integer overflow results in a heap-based buffer overflow condition where the application attempts to write data beyond the allocated memory boundaries. The flaw is categorized under CWE-190 as an integer overflow vulnerability, which directly enables memory corruption and potential privilege escalation.
The operational impact of this vulnerability is severe and multifaceted. Untrusted applications and applets can exploit this flaw to gain elevated privileges within the Java runtime environment, potentially allowing them to execute arbitrary code with the privileges of the user running the Java application. This represents a significant security risk in environments where applets are executed with elevated permissions or where the Java runtime is used in enterprise applications. The vulnerability can be particularly dangerous in web environments where applets are loaded from untrusted sources, as attackers can craft malicious Pack200 files that trigger the overflow when opened by a victim's browser.
From an attack framework perspective, this vulnerability aligns with techniques described in the MITRE ATT&CK framework under the privilege escalation and code execution domains. The attack requires an attacker to deliver a malicious Pack200 file to a victim who is running an affected Java version, typically through web-based delivery mechanisms or social engineering. The exploitation process involves crafting a file that, when processed by the vulnerable unpack200 utility, causes the integer overflow to result in memory corruption. This corruption can then be leveraged to execute arbitrary code or manipulate program execution flow, potentially leading to complete system compromise.
The recommended mitigations for this vulnerability include immediate patching of affected Java installations to the latest available versions that contain fixes for the integer overflow issue. Organizations should also implement strict application whitelisting policies to prevent execution of untrusted Pack200 files and consider disabling Pack200 decompression functionality where it is not required. Network-level controls such as content filtering and web application firewalls can help prevent delivery of malicious Pack200 files to affected systems. Additionally, users should be educated about the risks of executing untrusted Java applets and the importance of keeping Java installations up to date with security patches. The vulnerability serves as a reminder of the critical importance of proper input validation and integer overflow protection in security-critical applications, particularly in runtime environments that process untrusted data.