Ubuntu update for krb5
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 2 |
| CVE-ID | CVE-2021-36222 CVE-2021-37750 |
| CWE-ID | CWE-476 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software |
Ubuntu Operating systems & Components / Operating system krb5-k5tls (Ubuntu package) Operating systems & Components / Operating system package or component krb5-kdc (Ubuntu package) Operating systems & Components / Operating system package or component krb5-kdc-ldap (Ubuntu package) Operating systems & Components / Operating system package or component krb5-pkinit (Ubuntu package) Operating systems & Components / Operating system package or component |
| Vendor | Canonical Ltd. |
Security Bulletin
This security bulletin contains information about 2 vulnerabilities.
1) NULL pointer dereference
EUVDB-ID: #VU55287
Risk: Medium
CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID: CVE-2021-36222
CWE-ID:
CWE-476 - NULL Pointer Dereference
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in kdc/kdc_preauth_ec.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5). A remote attacker can send a request containing a PA-ENCRYPTED-CHALLENGE padata element without using FAST and perform a denial of service (DoS) attack.
MitigationUpdate the affected package krb5 to the latest version.
Vulnerable software versionsUbuntu: 18.04 - 20.04
krb5-k5tls (Ubuntu package): before 1.16-2ubuntu0.4
krb5-kdc (Ubuntu package): before 1.16-2ubuntu0.4
krb5-kdc-ldap (Ubuntu package): before 1.16-2ubuntu0.4
krb5-pkinit (Ubuntu package): before 1.16-2ubuntu0.4
CPE2.3- cpe:2.3:o:canonical:ubuntu:18.04:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu:20.04:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:krb5-k5tls_ubuntu_package:*:*:*:*:*:ubuntu:*:*
- cpe:2.3:o:canonical:krb5-kdc_ubuntu_package:*:*:*:*:*:ubuntu:*:*
- cpe:2.3:o:canonical:krb5-kdc-ldap_ubuntu_package:*:*:*:*:*:ubuntu:*:*
- cpe:2.3:o:canonical:krb5-pkinit_ubuntu_package:*:*:*:*:*:ubuntu:*:*
https://ubuntu.com/security/notices/USN-5959-1
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) NULL pointer dereference
EUVDB-ID: #VU56828
Risk: Medium
CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID: CVE-2021-37750
CWE-ID:
CWE-476 - NULL Pointer Dereference
Exploit availability: No
DescriptionThe vulnerability allows a remote user to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in the Key Distribution Center (KDC) in kdc/do_tgs_req.c. A remote user can pass specially crafted data via the FAST inner body that lacks a server field, trigger a NULL pointer dereference error and perform a denial of service (DoS) attack.
Update the affected package krb5 to the latest version.
Vulnerable software versionsUbuntu: 18.04 - 20.04
krb5-k5tls (Ubuntu package): before 1.16-2ubuntu0.4
krb5-kdc (Ubuntu package): before 1.16-2ubuntu0.4
krb5-kdc-ldap (Ubuntu package): before 1.16-2ubuntu0.4
krb5-pkinit (Ubuntu package): before 1.16-2ubuntu0.4
CPE2.3- cpe:2.3:o:canonical:krb5-k5tls_ubuntu_package:*:*:*:*:*:ubuntu:*:*
- cpe:2.3:o:canonical:krb5-kdc_ubuntu_package:*:*:*:*:*:ubuntu:*:*
- cpe:2.3:o:canonical:krb5-kdc-ldap_ubuntu_package:*:*:*:*:*:ubuntu:*:*
- cpe:2.3:o:canonical:krb5-pkinit_ubuntu_package:*:*:*:*:*:ubuntu:*:*
https://ubuntu.com/security/notices/USN-5959-1
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
