An issue was discovered in Heimdal Thor agent versions 3.4.2 and before on Windows and 2.6.9 and before on macOS, allows attackers to cause a denial of service (DoS) via the Threat To Process Correlation threat prevention module. NOTE: Heimdal asserts this is not a valid vulnerability. Their DNS Security for Endpoint solution includes an optional feature to provide extra information on the originating process that made a DNS request. The lack of process identification in DNS logs is therefore falsely categorized as a DoS issue.

An issue was discovered in Heimdal Thor agent versions 3.4.2 and before 3.7.0 on Windows, allows attackers to bypass USB access restrictions, execute arbitrary code, and obtain sensitive information via Next-Gen Antivirus component. NOTE: Heimdal argues that the limitation described here is a Microsoft Windows issue, not a Heimdal specific vulnerability. The USB control solution by Heimdal is meant to manage Microsoft Windows native USB restrictions. They maintain that their solution functions as a management layer over Windows settings and is not to blame for limitations in Windows' detection capabilities.

An issue was discovered in Heimdal Thor agent versions 3.4.2 and before on Windows and 2.6.9 and before on macOS, allows attackers to bypass network filtering, execute arbitrary code, and obtain sensitive information via DarkLayer Guard threat prevention module. NOTE: Heimdal disputes the validity of this issue arguing that their DNS Security for Endpoint filters DNS traffic on the endpoint by intercepting system-generated DNS requests. The product was not designed to intercept DNS requests from third-party solutions.

The Heimdal Software Kerberos 5 implementation is vulnerable to a null pointer dereferance. An attacker with network access to an application that depends on the vulnerable code path can cause the application to crash.

The fix for CVE-2022-3437 included changing memcmp to be constant time and a workaround for a compiler bug by adding "!= 0" comparisons to the result of memcmp. When these patches were backported to the heimdal-7.7.1 and heimdal-7.8.0 branches (and possibly other branches) a logic inversion sneaked in causing the validation of message integrity codes in gssapi/arcfour to be inverted.

Heimdal before 7.7.1 allows attackers to cause a NULL pointer dereference in a SPNEGO acceptor via a preferred_mech_type of GSS_C_NO_OID and a nonzero initial_response value to send_accept.

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."

Heimdal before 7.7.1 allows remote attackers to execute arbitrary code because of an invalid free in the ASN.1 codec used by the Key Distribution Center (KDC).

Heimdal is an implementation of ASN.1/DER, PKIX, and Kerberos. Versions prior to 7.7.1 are vulnerable to a denial of service vulnerability in Heimdal's PKI certificate validation library, affecting the KDC (via PKINIT) and kinit (via PKINIT), as well as any third-party applications using Heimdal's libhx509. Users should upgrade to Heimdal 7.7.1 or 7.8. There are no known workarounds for this issue.

Heimdal.Wizard.exe installer in Heimdal Premium Security 2.5.395 and earlier has insecure permissions, which allows unprivileged local users to elevate privileges to SYSTEM via the "Browse For Folder" window accessible by triggering a "Repair" on the MSI package located in C:\Windows\Installer.