# CVE-2024-37370: MIT Kerberos 5 message truncation in GSS krb5 wrap token

Source: https://junglewise.ai/threats/cve-2024-37370-mit-kerberos-5-message-truncation-in-gss-krb5-wrap-token  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2024-06-28. Updated: 2026-05-12  
License: CC BY 4.0 with a link back

CVE-2024-37370 · Severity: high · CVSS 7.5 · Published 2024-06-28

MIT Kerberos 5 is a widely used authentication protocol that allows nodes communicating over a non-secure network to prove their identity to one another in a secure manner. A vulnerability in how it handles secure message tokens could allow an attacker to modify network traffic, causing applications to receive incomplete or truncated data. This could lead to information disclosure or disrupt the normal operation of services relying on Kerberos for secure communication.

Technologies: [Mit Kerberos 5](https://junglewise.ai/threats/technologies/kerberos-5). Vendors: [Mit](https://junglewise.ai/threats/vendors/mit), [Siemens](https://junglewise.ai/threats/vendors/siemens).

## Quick answers

**Is CVE-2024-37370 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2024-37370 being exploited in the wild.

**How severe is CVE-2024-37370?** High severity, with a CVSS score of 7.5, published 28 June 2024.

**Which products and versions are affected?** Siemens SIMATIC S7-1500 CPU 1518 PN/DP MFP >= V3.1.5.

**Is there a fix for CVE-2024-37370?** A patch was published on 2024-06-28: Fixed in MIT krb5 1.21.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2024-37370 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2024-37370?** Check whether you run Mit Kerberos 5 or Siemens SIMATIC S7-1500 CPU 1518 PN/DP MFP at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A vulnerability exists in MIT Kerberos 5 (krb5) before version 1.21.3 within the GSS-API implementation. The root cause is the insufficient verification of the plaintext 'Extra Count' field in confidential GSS krb5 wrap tokens (CFX wrap tokens). An unauthenticated remote attacker can modify this field, which is not properly validated against the encrypted header during the unwrapping process in functions such as gss_krb5int_unseal_token_v3(). This manipulation causes the unwrapped token to appear truncated to the receiving application. While the primary impact is categorized as confidentiality loss in some assessments, it effectively allows for data integrity manipulation that results in truncated application data. The issue is fixed in MIT krb5 version 1.21.3.

## Affected products

- MIT Kerberos 5 (krb5) up to (excluding) 1.21.3
- Siemens SIMATIC S7-1500 CPU 1518 PN/DP MFP >= V3.1.5

## Timeline

- 2024-06-28: disclosed
- 2024-06-28: advisory
- 2024-06-28: patched: Fixed in MIT krb5 1.21.3

## References

- [https://github.com/krb5/krb5/commit/55fbf435edbe2e92dd8101669b1ce7144bc96fef](https://github.com/krb5/krb5/commit/55fbf435edbe2e92dd8101669b1ce7144bc96fef)
- [https://web.mit.edu/kerberos/www/advisories/](https://web.mit.edu/kerberos/www/advisories/)
- [https://security.netapp.com/advisory/ntap-20241108-0007/](https://security.netapp.com/advisory/ntap-20241108-0007/)
- [https://cert-portal.siemens.com/productcert/html/ssa-082556.html](https://cert-portal.siemens.com/productcert/html/ssa-082556.html)

## Related threats

- [MIT Kerberos 5 denial of service in ASN.1 SEQUENCE OF decoding](https://junglewise.ai/threats/cve-2026-119079-decode-sequence-of-in-lib-krb5-asn-1-asn1-encode-c-in-mit)
- [MIT Kerberos 5 kadmind memory exhaustion in AUTH_GSSAPI](https://junglewise.ai/threats/cve-2026-112323-the-auth-gssapi-handler-in-lib-rpc-svc-auth-gssapi-c-in-mit)
- [MIT Kerberos 5 denial of service in kadmind AUTH_GSSAPI cleanup](https://junglewise.ai/threats/cve-2026-112322-clean-client-in-lib-rpc-svc-auth-gssapi-c-in-mit-kerberos-5-aka)
- [MIT Kerberos memory exhaustion in AUTH_GSSAPI handler](https://junglewise.ai/threats/cve-2026-112321-the-auth-gssapi-handler-in-lib-rpc-svc-auth-gssapi-c-in-mit)
- [MIT Kerberos 5 memory exhaustion via GSS-RPC authentication context leak](https://junglewise.ai/threats/cve-2026-112320-the-gss-rpc-transport-layer-in-mit-kerberos-5-aka-krb5-1-4-and)