CVE-2019-11068 in Java SE
Summary
by MITRE
libxslt through 1.1.33 allows bypass of a protection mechanism because callers of xsltCheckRead and xsltCheckWrite permit access even upon receiving a -1 error code. xsltCheckRead can return -1 for a crafted URL that is not actually invalid and is subsequently loaded.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 05/29/2026
The vulnerability identified as CVE-2019-11068 resides within the libxslt library version 1.1.33 and earlier, representing a critical security flaw that undermines the intended access control mechanisms. This issue specifically affects the xsltCheckRead and xsltCheckWrite functions which are designed to validate and restrict access to external resources during XSLT transformations. The flaw manifests when these functions return a -1 error code to indicate potential access violations, yet the calling functions fail to properly interpret this signal and continue with the operation, effectively bypassing the protection mechanism.
The technical implementation of this vulnerability stems from a logic error in how the library handles error codes from its resource validation functions. When xsltCheckRead encounters a crafted URL, it may return -1 to signal a potential security issue, but the calling code does not properly terminate or reject the operation based on this negative response. This allows attackers to craft malicious URLs that appear to trigger validation errors but are actually loaded and processed by the system. The flaw operates at the intersection of input validation and access control, where the system's attempt to prevent unauthorized resource access is circumvented through improper error handling.
This vulnerability has significant operational impact as it enables attackers to bypass intended security restrictions during XSLT processing operations. Systems utilizing libxslt for document transformation and processing become vulnerable to unauthorized access to external resources, potentially allowing for information disclosure, remote code execution, or denial of service attacks. The vulnerability affects any application that relies on libxslt for processing XSLT transformations and may be exploited through crafted XML documents that contain malicious URLs in their transformation parameters. The bypass mechanism operates silently, making detection difficult and potentially allowing for prolonged unauthorized access to system resources.
From a cybersecurity perspective, this vulnerability aligns with CWE-250, which addresses "Execute Code from Untrusted Input," and represents a classic case of improper error handling that undermines security controls. The flaw also relates to ATT&CK technique T1059, which involves executing malicious code through command-line interfaces, as the bypassed protection mechanisms could enable attackers to load and execute unauthorized code. Organizations using affected versions of libxslt should immediately implement mitigations including updating to patched versions, implementing additional input validation, and monitoring for suspicious XSLT processing activities. The vulnerability demonstrates the critical importance of proper error code interpretation and the potential consequences of failing to enforce security checks at all levels of system operation.