CVE-2022-42898 in MySQL Cluster
Summary
by MITRE • 12/25/2022
PAC parsing in MIT Kerberos 5 (aka krb5) before 1.19.4 and 1.20.x before 1.20.1 has integer overflows that may lead to remote code execution (in KDC, kadmind, or a GSS or Kerberos application server) on 32-bit platforms (which have a resultant heap-based buffer overflow), and cause a denial of service on other platforms. This occurs in krb5_pac_parse in lib/krb5/krb/pac.c. Heimdal before 7.7.1 has "a similar bug."
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Analysis
by VulDB Data Team • 08/28/2026
The vulnerability CVE-2022-42898 represents a critical security flaw in the MIT Kerberos 5 authentication system that affects versions prior to 1.19.4 and 1.20.1. This issue stems from improper handling of PAC (Privilege Attribute Certificate) parsing within the kerberos implementation, specifically in the krb5_pac_parse function located in lib/krb5/krb/pac.c. The vulnerability manifests as integer overflows that can result in heap-based buffer overflows on 32-bit platforms, potentially enabling remote code execution. The flaw impacts the Key Distribution Center (KDC), kadmind server, or any GSS or Kerberos application server that processes PAC data, making it particularly dangerous in enterprise authentication environments where these services are heavily utilized.
The technical nature of this vulnerability involves integer overflow conditions that occur during the parsing of PAC data structures, which are essential components of Microsoft's Kerberos implementation used for authentication and authorization. When processing maliciously crafted PAC data, the integer overflows cause memory allocation calculations to produce incorrect buffer sizes, leading to heap corruption on 32-bit systems where the memory layout is more constrained. This heap-based buffer overflow creates opportunities for attackers to execute arbitrary code with the privileges of the affected service. The vulnerability is classified under CWE-190 as an Integer Overflow or Wraparound, which is a well-known class of memory safety issues that frequently leads to exploitable conditions. The ATT&CK framework would categorize this under T1190 for Exploit Public-Facing Application, as the vulnerability affects network services that are commonly exposed to external threats.
The operational impact of this vulnerability extends beyond simple code execution, as it can lead to complete compromise of authentication systems that rely on Kerberos. On 32-bit platforms, the heap overflow can be exploited to gain arbitrary code execution, potentially allowing attackers to escalate privileges and establish persistent access to network resources. Even on 64-bit systems where direct code execution may not be possible, the vulnerability can still cause denial of service conditions that disrupt legitimate authentication services. The widespread use of Kerberos in enterprise environments, particularly in Active Directory domains, means that exploitation of this vulnerability can have cascading effects across multiple systems. The fact that Heimdal implementations before version 7.7.1 contain a similar vulnerability indicates this is a systemic issue within Kerberos implementations that requires comprehensive patching across all affected systems.
Organizations should prioritize immediate patching of all affected MIT Kerberos installations to prevent exploitation, particularly in environments where 32-bit systems are still in use. Additional mitigations include implementing network segmentation to limit exposure of Kerberos services, monitoring for unusual PAC data processing patterns, and ensuring that all Kerberos servers are regularly updated according to vendor security advisories. Security teams should also consider implementing intrusion detection systems that can identify exploitation attempts targeting this specific vulnerability. The vulnerability demonstrates the critical importance of proper integer handling in security-critical code, as even seemingly minor flaws in memory management can result in significant security breaches. Organizations that have not yet migrated to 64-bit platforms should consider this vulnerability as a compelling reason to accelerate such transitions, as 64-bit systems provide better protection against heap-based buffer overflow exploitation techniques.