CVE-2017-20230 in Storable
Summary
by MITRE • 04/21/2026
Storable versions before 3.05 for Perl has a stack overflow.
The retrieve_hook function stored the length of the class name into a signed integer but in read operations treated the length as unsigned. This allowed an attacker to craft data that could trigger the overflow.
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Analysis
by VulDB Data Team • 05/23/2026
The vulnerability in Storable versions prior to 3.05 represents a critical stack overflow condition that stems from improper handling of integer types during serialization and deserialization operations. This flaw exists within the retrieve_hook function where the system stores the length of class names using a signed integer data type during the storage phase. However, during subsequent read operations, the system treats this stored length value as an unsigned integer, creating a fundamental type mismatch that can be exploited by malicious actors. The discrepancy between signed and unsigned integer handling creates a scenario where an attacker can craft specially formatted data that causes the length value to exceed the maximum representable value for a signed integer, leading to unexpected behavior during memory allocation.
This vulnerability operates at the intersection of multiple security concerns including buffer overflows, integer overflow conditions, and memory corruption issues. The flaw aligns with CWE-190, which specifically addresses integer overflow and underflow conditions, and more broadly with CWE-121, dealing with stack-based buffer overflow scenarios. The attack vector leverages the difference in how signed and unsigned integers are processed by the system, allowing an attacker to manipulate the stored class name length in such a way that when the unsigned interpretation is applied during retrieval, it results in a massive allocation request that overflows the stack space available for the operation. This type of vulnerability is particularly dangerous because it can lead to arbitrary code execution when the stack overflow corrupts adjacent memory locations, potentially allowing attackers to overwrite return addresses or other critical program state information.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it can enable complete system compromise when exploited properly. Attackers who can control the data being deserialized through Storable can craft payloads that cause the application to allocate enormous amounts of stack memory, potentially leading to crashes or more severe exploitation opportunities. The vulnerability affects any system that utilizes Storable versions before 3.05 for Perl, particularly web applications or services that deserialize untrusted data from external sources. According to ATT&CK framework category T1203, this vulnerability could be leveraged for process injection or code execution through memory corruption techniques, while the technique T1059 involving command and scripting interpreter usage could be employed in subsequent exploitation phases if successful stack overflow occurs.
Mitigation strategies for this vulnerability require immediate patching to version 3.05 or later of the Storable module, which resolves the integer type inconsistency in the retrieve_hook function. Organizations should also implement strict input validation and sanitization for all deserialization operations, particularly when processing data from untrusted sources. Additional defensive measures include monitoring for unusual memory allocation patterns and implementing heap-based memory protection mechanisms such as stack canaries or address space layout randomization. Security teams should also consider implementing network segmentation and access controls to limit the potential impact of successful exploitation attempts, while maintaining regular vulnerability scanning to identify other potentially affected systems or applications that may utilize vulnerable versions of the Storable module.