# CVE-2021-37750: krb5-devel: Kerberos is a network authentication system, which can improve the security of your network by eliminating the insecu... CVE-2021-37750 is fixed in 26 products on 1 platform, first by krb5-admin-server 1.16-2ubuntu0.4, released August 22, 2021. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2021-37750 - Priority: Routine - CVSS: 6.5 (Moderate) - EPSS: 0.0251 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Aug 22, 2021 ## Description Kerberos is a network authentication system, which can improve the security of your network by eliminating the insecure practice of sending passwords over the network in unencrypted form. It allows clients and servers to authenticate to each other with the help of a trusted third party, the Kerberos key distribution center (KDC). Security Fix(es): * krb5: Sending a request containing PA-ENCRYPTED-CHALLENGE padata element without using FAST could result in NULL dereference in KDC which leads to DoS (CVE-2021-36222) * krb5: NULL pointer dereference in process_tgs_req() in kdc/do_tgs_req.c via a FAST inner body that lacks server field (CVE-2021-37750) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | krb5-admin-server Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [krb5-admin-server 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-krb5-admin-server-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | krb5-admin-server Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [krb5-admin-server 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-krb5-admin-server-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | krb5-devel RHEL 8 | 0:1.18.2-8.3.el8_4 | [RHSA-2021:3576](https://patchblox.com/security/data/fix/linux/rhsa-2021-3576.md) | Sep 21, 2021 | | Linux | krb5-devel ol 8 | 0:1.18.2-8.3.el8_4 | [ELSA-2021-3576](https://patchblox.com/security/data/fix/linux/elsa-2021-3576.md) | Sep 23, 2021 | | Linux | krb5-gss-samples Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [krb5-gss-samples 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-krb5-gss-samples-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | krb5-gss-samples Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [krb5-gss-samples 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-krb5-gss-samples-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | krb5-k5tls Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [krb5-k5tls 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-krb5-k5tls-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | krb5-k5tls Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [krb5-k5tls 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-krb5-k5tls-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | krb5-kdc Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [krb5-kdc 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-krb5-kdc-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | krb5-kdc Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [krb5-kdc 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-krb5-kdc-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | krb5-kdc-ldap Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [krb5-kdc-ldap 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-krb5-kdc-ldap-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | krb5-kdc-ldap Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [krb5-kdc-ldap 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-krb5-kdc-ldap-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | krb5-kpropd Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [krb5-kpropd 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-krb5-kpropd-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | krb5-kpropd Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [krb5-kpropd 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-krb5-kpropd-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | krb5-libs RHEL 8 | 0:1.18.2-8.3.el8_4 | [RHSA-2021:3576](https://patchblox.com/security/data/fix/linux/rhsa-2021-3576.md) | Sep 21, 2021 | | Linux | krb5-libs ol 8 | 0:1.18.2-8.3.el8_4 | [ELSA-2021-3576](https://patchblox.com/security/data/fix/linux/elsa-2021-3576.md) | Sep 23, 2021 | | Linux | krb5-locales Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [krb5-locales 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-krb5-locales-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | krb5-locales Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [krb5-locales 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-krb5-locales-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | krb5-multidev Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [krb5-multidev 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-krb5-multidev-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | krb5-multidev Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [krb5-multidev 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-krb5-multidev-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | krb5-otp Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [krb5-otp 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-krb5-otp-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | krb5-otp Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [krb5-otp 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-krb5-otp-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | krb5-pkinit RHEL 8 | 0:1.18.2-8.3.el8_4 | [RHSA-2021:3576](https://patchblox.com/security/data/fix/linux/rhsa-2021-3576.md) | Sep 21, 2021 | | Linux | krb5-pkinit Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [krb5-pkinit 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-krb5-pkinit-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | krb5-pkinit Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [krb5-pkinit 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-krb5-pkinit-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | krb5-pkinit ol 8 | 0:1.18.2-8.3.el8_4 | [ELSA-2021-3576](https://patchblox.com/security/data/fix/linux/elsa-2021-3576.md) | Sep 23, 2021 | | Linux | krb5-server RHEL 8 | 0:1.18.2-8.3.el8_4 | [RHSA-2021:3576](https://patchblox.com/security/data/fix/linux/rhsa-2021-3576.md) | Sep 21, 2021 | | Linux | krb5-server ol 8 | 0:1.18.2-8.3.el8_4 | [ELSA-2021-3576](https://patchblox.com/security/data/fix/linux/elsa-2021-3576.md) | Sep 23, 2021 | | Linux | krb5-server-ldap RHEL 8 | 0:1.18.2-8.3.el8_4 | [RHSA-2021:3576](https://patchblox.com/security/data/fix/linux/rhsa-2021-3576.md) | Sep 21, 2021 | | Linux | krb5-server-ldap ol 8 | 0:1.18.2-8.3.el8_4 | [ELSA-2021-3576](https://patchblox.com/security/data/fix/linux/elsa-2021-3576.md) | Sep 23, 2021 | | Linux | krb5-user Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [krb5-user 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-krb5-user-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | krb5-user Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [krb5-user 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-krb5-user-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | krb5-workstation RHEL 8 | 0:1.18.2-8.3.el8_4 | [RHSA-2021:3576](https://patchblox.com/security/data/fix/linux/rhsa-2021-3576.md) | Sep 21, 2021 | | Linux | krb5-workstation ol 8 | 0:1.18.2-8.3.el8_4 | [ELSA-2021-3576](https://patchblox.com/security/data/fix/linux/elsa-2021-3576.md) | Sep 23, 2021 | | Linux | libgssapi-krb5-2 Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [libgssapi-krb5-2 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libgssapi-krb5-2-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | libgssapi-krb5-2 Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [libgssapi-krb5-2 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libgssapi-krb5-2-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | libgssrpc4 Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [libgssrpc4 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libgssrpc4-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | libgssrpc4 Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [libgssrpc4 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libgssrpc4-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | libk5crypto3 Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [libk5crypto3 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libk5crypto3-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | libk5crypto3 Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [libk5crypto3 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libk5crypto3-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | libkadm5 RHEL 8 | 0:1.18.2-8.3.el8_4 | [RHSA-2021:3576](https://patchblox.com/security/data/fix/linux/rhsa-2021-3576.md) | Sep 21, 2021 | | Linux | libkadm5 ol 8 | 0:1.18.2-8.3.el8_4 | [ELSA-2021-3576](https://patchblox.com/security/data/fix/linux/elsa-2021-3576.md) | Sep 23, 2021 | | Linux | libkadm5clnt-mit11 Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [libkadm5clnt-mit11 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libkadm5clnt-mit11-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | libkadm5clnt-mit11 Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [libkadm5clnt-mit11 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libkadm5clnt-mit11-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | libkadm5srv-mit11 Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [libkadm5srv-mit11 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libkadm5srv-mit11-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | libkadm5srv-mit11 Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [libkadm5srv-mit11 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libkadm5srv-mit11-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | libkdb5-9 Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [libkdb5-9 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libkdb5-9-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | libkdb5-9 Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [libkdb5-9 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libkdb5-9-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | libkrad0 Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [libkrad0 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libkrad0-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | libkrad0 Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [libkrad0 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libkrad0-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | libkrb5-3 Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [libkrb5-3 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libkrb5-3-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | libkrb5-3 Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [libkrb5-3 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libkrb5-3-1.17-6ubuntu4.3.md) | Aug 22, 2021 | | Linux | libkrb5support0 Ubuntu 18.04.6 LTS (bionic) | 1.16-2ubuntu0.4 | [libkrb5support0 1.16-2ubuntu0.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libkrb5support0-1.16-2ubuntu0.4.md) | Aug 22, 2021 | | Linux | libkrb5support0 Ubuntu 20.04 LTS (focal) | 1.17-6ubuntu4.3 | [libkrb5support0 1.17-6ubuntu4.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libkrb5support0-1.17-6ubuntu4.3.md) | Aug 22, 2021 | --- Data as of 2026-11-09T13:31:49Z UTC. 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