CVE-2025-64786 in Acrobat Reader
Summary
by MITRE • 12/09/2025
Acrobat Reader versions 24.001.30264, 20.005.30793, 25.001.20982, 24.001.30273, 20.005.30803 and earlier are affected by an Improper Verification of Cryptographic Signature vulnerability that could result in a Security feature bypass. An attacker could leverage this vulnerability to gain limited unauthorized write access. Exploitation of this issue does not require user interaction.
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Analysis
by VulDB Data Team • 12/13/2025
The vulnerability identified as CVE-2025-64786 represents a critical weakness in Adobe Acrobat Reader's cryptographic signature verification mechanisms, affecting multiple version lines including 20.005.x, 24.001.x, and 25.001.x series. This flaw resides in the software's inability to properly validate digital signatures, creating a pathway for attackers to bypass essential security controls that are meant to protect document integrity and authenticity. The vulnerability stems from insufficient cryptographic verification processes that allow malicious actors to manipulate or forge digital signatures without detection, fundamentally undermining the trust model that digital signatures are designed to establish. This weakness directly impacts the security architecture of Acrobat Reader by creating a scenario where the application cannot reliably distinguish between legitimate and maliciously altered documents.
The technical implementation of this vulnerability manifests through flawed signature validation routines that fail to properly authenticate cryptographic signatures before granting access permissions or executing document operations. When Acrobat Reader processes documents with digital signatures, the affected versions perform inadequate checks on the signature's authenticity, allowing attackers to craft manipulated signatures that pass validation. This occurs due to improper handling of cryptographic verification algorithms or insufficient validation of signature parameters, potentially enabling attackers to exploit the signature verification process to gain unauthorized write access to system resources. The vulnerability's classification aligns with CWE-327, which addresses weak cryptographic algorithms, and CWE-331, which covers insufficient entropy in cryptographic systems. The flaw operates at the cryptographic protocol level, where the software's security controls fail to provide adequate protection against signature forgery attacks.
The operational impact of CVE-2025-64786 extends beyond simple document integrity concerns, as it enables attackers to achieve limited but unauthorized write access to system resources through the bypassed security features. This vulnerability can be exploited without requiring any user interaction, making it particularly dangerous as it can be leveraged automatically by malicious actors without the need for social engineering or user deception. The security feature bypass allows attackers to potentially modify documents, inject malicious content, or manipulate system behavior through crafted signature structures. The lack of user interaction requirement places this vulnerability in the ATT&CK framework under technique T1059.007 for command and scripting interpreter, as attackers can potentially execute malicious code through manipulated documents. This automated exploitation capability significantly increases the attack surface and reduces the time required for successful compromise.
Mitigation strategies for CVE-2025-64786 should prioritize immediate patching of all affected Acrobat Reader versions, with security administrators implementing comprehensive monitoring for suspicious document processing activities. Organizations should consider implementing additional signature validation controls and restricting document processing capabilities for untrusted sources. The vulnerability's nature suggests that implementing stronger cryptographic signature verification mechanisms, including proper certificate chain validation and enhanced signature parameter checking, would provide effective protection. Security teams should also consider deploying network-based intrusion detection systems to monitor for exploitation attempts and establish baseline behaviors for document processing activities. Regular security assessments of document handling processes and cryptographic implementations should be conducted to identify similar weaknesses in other software components. The remediation approach must address the root cause through proper cryptographic verification implementation rather than temporary workarounds, ensuring that digital signature validation processes provide adequate protection against forged or manipulated signatures.