CVE-2017-8829 in lintian
Summary
by MITRE
Deserialization vulnerability in lintian through 2.5.50.3 allows attackers to trigger code execution by requesting a review of a source package with a crafted YAML file.
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Analysis
by VulDB Data Team • 08/19/2024
The CVE-2017-8829 vulnerability represents a critical deserialization flaw in lintian version 2.5.50.3 and earlier, exposing systems to remote code execution attacks through maliciously crafted YAML files. This vulnerability specifically affects the package review process within lintian, a tool used for checking debian packages for compliance with debian policy guidelines. The flaw arises from insufficient input validation and unsafe deserialization practices during the processing of YAML formatted data structures. Attackers can exploit this weakness by constructing a specially crafted YAML file that, when processed by lintian during source package review, triggers arbitrary code execution on the target system. The vulnerability demonstrates a classic insecure deserialization pattern that aligns with CWE-502, which categorizes deserialization of untrusted data as a significant security risk. This issue falls under the ATT&CK technique T1203, where adversaries leverage application vulnerabilities to execute arbitrary code, making it particularly dangerous in automated build and review environments where lintian processes untrusted package data.
The technical implementation of this vulnerability stems from lintian's failure to properly sanitize or validate YAML input before deserializing it into executable code objects. When a user requests a review of a source package containing malicious YAML, the tool's deserialization mechanism interprets the crafted data as legitimate instructions rather than malicious payloads. This occurs because the application relies on default deserialization behavior without implementing proper input validation or object type restrictions. The vulnerability is particularly severe in continuous integration environments where lintian automatically processes incoming packages, as attackers can leverage this weakness to execute arbitrary commands with the privileges of the lintian process. The deserialization chain typically involves creating malicious objects that, when instantiated through the YAML parser, trigger code execution through method calls or constructor invocations within the deserialization process itself.
The operational impact of CVE-2017-8829 extends beyond simple code execution to encompass complete system compromise when exploited in appropriate environments. Systems running vulnerable versions of lintian become potential attack vectors for adversaries seeking to establish persistent access or escalate privileges within debian-based development environments. The vulnerability affects not only individual developer workstations but also automated build servers, package repositories, and continuous integration pipelines that rely on lintian for quality assurance. Attackers can leverage this weakness to install backdoors, exfiltrate sensitive data, or use the compromised system as a launch point for further attacks within the network. Organizations using lintian for automated package validation face significant risk exposure, particularly in open source development environments where untrusted packages are regularly processed. The vulnerability also impacts security monitoring systems that rely on lintian for package integrity checks, as malicious packages could bypass detection mechanisms.
Mitigation strategies for CVE-2017-8829 require immediate patching of affected lintian installations to version 2.5.50.4 or later, which contains the necessary deserialization safeguards. Organizations should implement strict input validation and sanitization measures for all YAML processing within their systems, particularly in automated workflows. Network segmentation and access controls should be implemented to limit exposure of systems running lintian to untrusted package data sources. Security monitoring should be enhanced to detect unusual patterns in package review activities, particularly when processing packages from unknown or untrusted sources. The implementation of sandboxing mechanisms for package review processes can provide additional protection layers, isolating the deserialization operations from the broader system. Organizations should also consider implementing automated vulnerability scanning for their package repositories to identify and remediate similar issues in other tools that process untrusted data formats. Regular security assessments of development environments and continuous monitoring for similar deserialization vulnerabilities across the software supply chain are essential for maintaining security posture. This vulnerability highlights the critical importance of secure coding practices and proper input validation in preventing exploitation of deserialization flaws, particularly in tools that process external data in automated environments.