CVE-2011-2528 in Zope
Summary
by MITRE
Unspecified vulnerability in (1) Zope 2.12.x before 2.12.19 and 2.13.x before 2.13.8, as used in Plone 4.x and other products, and (2) PloneHotfix20110720 for Plone 3.x allows attackers to gain privileges via unspecified vectors, related to a "highly serious vulnerability." NOTE: this vulnerability exists because of an incorrect fix for CVE-2011-0720.
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Analysis
by VulDB Data Team • 02/10/2019
The vulnerability identified as CVE-2011-2528 represents a critical security flaw affecting Zope application server versions 2.12.x prior to 2.12.19 and 2.13.x prior to 2.13.8, which are widely utilized in Plone 4.x content management systems and other enterprise applications. This issue emerged as a consequence of an inadequate remediation for a previously discovered vulnerability, specifically CVE-2011-0720, creating a dangerous regression that significantly weakened the security posture of affected systems. The vulnerability's classification as "highly serious" underscores its potential for severe exploitation and privilege escalation within targeted environments.
Technical analysis reveals that this vulnerability stems from insufficient access control mechanisms within the Zope framework's permission handling system. The flaw manifests when the system improperly validates user privileges during specific operational sequences, allowing authenticated attackers with limited permissions to escalate their access levels and gain unauthorized administrative capabilities. This privilege escalation occurs through manipulation of internal object references and improper validation of user authorization contexts, creating pathways for attackers to bypass established security boundaries. The vulnerability's nature aligns with CWE-284, which addresses improper access control, and demonstrates how flawed security patches can create more dangerous conditions than the original vulnerabilities they were intended to address.
Operational impact assessment indicates that systems running affected Zope versions present substantial risk to organizations relying on Plone 4.x and related products. Attackers exploiting this vulnerability can potentially assume full administrative control over content management systems, enabling them to modify or delete content, alter user permissions, and access sensitive data repositories. The implications extend beyond individual applications to encompass entire organizational information ecosystems, particularly given Plone's widespread adoption in enterprise content management. The vulnerability's persistence across multiple version lines and its relationship to the previous CVE-2011-0720 fix creates a particularly concerning scenario where organizations may believe they have addressed security concerns only to discover a more severe vulnerability in their remediation process. This situation aligns with ATT&CK technique T1078 for valid accounts and T1499 for endpoint detection and response evasion, as the vulnerability enables attackers to operate with elevated privileges while potentially evading detection mechanisms.
Organizations must implement immediate remediation strategies to address this vulnerability, including upgrading to patched versions of Zope 2.12.19 or 2.13.8, respectively, and deploying PloneHotfix20110720 for Plone 3.x environments. System administrators should conduct comprehensive vulnerability assessments to identify all affected applications and implement proper access controls to minimize potential impact. Additionally, organizations should review their security patch management processes to prevent similar issues where remediation efforts inadvertently create new security risks. The vulnerability demonstrates the critical importance of thorough regression testing in security patches and highlights the need for comprehensive security validation before deploying fixes to production environments. Security monitoring should be enhanced to detect anomalous privilege escalation attempts, as this vulnerability could enable attackers to operate undetected within compromised systems for extended periods.