CVE-2015-8608 in Perl
Summary
by MITRE
The VDir::MapPathA and VDir::MapPathW functions in Perl 5.22 allow remote attackers to cause a denial of service (out-of-bounds read) and possibly execute arbitrary code via a crafted (1) drive letter or (2) pInName argument.
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Analysis
by VulDB Data Team • 09/01/2020
The vulnerability identified as CVE-2015-8608 affects Perl 5.22 and stems from improper input validation within the VDir::MapPathA and VDir::MapPathW functions. These functions handle path mapping operations for directory traversal and file access within the Perl interpreter. The flaw manifests when processing crafted drive letter specifications or pInName arguments that exceed expected boundaries, creating conditions where memory access occurs beyond allocated buffer limits. This out-of-bounds read condition represents a critical security weakness that can potentially be exploited to execute arbitrary code or cause system instability.
The technical implementation of this vulnerability involves the manipulation of input parameters passed to the VDir::MapPathA and VDir::MapPathW functions, which are part of Perl's internal directory handling mechanisms. When attackers provide specially crafted drive letter specifications or pInName arguments, the functions fail to properly validate the input length and boundaries before performing memory operations. This validation failure creates a scenario where the program attempts to read memory locations beyond the allocated buffer space, potentially exposing sensitive data or allowing attackers to manipulate program execution flow. The vulnerability operates at the intersection of buffer management and input sanitization, making it particularly dangerous in environments where Perl processes untrusted input.
From an operational perspective, this vulnerability presents significant risks to systems running Perl 5.22, particularly those exposed to untrusted input sources such as web applications, network services, or file processing systems. The potential for remote code execution means that attackers could leverage this flaw to gain unauthorized system access, escalate privileges, or establish persistent access points. The denial of service component ensures that even if code execution is not achieved, systems could become unavailable through memory corruption or process termination. Organizations utilizing Perl in production environments face substantial risk exposure, especially in scenarios involving file system operations or directory traversal functions.
Security mitigations for CVE-2015-8608 should prioritize immediate patching of Perl installations to versions that address the buffer validation issues in VDir::MapPathA and VDir::MapPathW functions. System administrators should implement input validation controls at application boundaries to prevent malformed drive letter or pInName arguments from reaching the vulnerable functions. Network segmentation and access controls can limit potential attack vectors by restricting exposure of Perl applications to untrusted inputs. Additionally, monitoring systems should be configured to detect anomalous behavior patterns that might indicate exploitation attempts, while application firewalls can provide additional layers of protection. The vulnerability aligns with CWE-125 out-of-bounds read and CWE-787 out-of-bounds write classifications, and represents a potential ATT&CK technique involving privilege escalation through memory corruption vulnerabilities. Organizations should also consider implementing runtime protections such as stack canaries or address space layout randomization to further reduce exploitation success rates.