Amazon Linux AMI update for samba
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 4 |
| CVE-ID | CVE-2017-2619 CVE-2016-2126 CVE-2016-2125 CVE-2017-7494 |
| CWE-ID | CWE-362 CWE-119 CWE-287 CWE-426 |
| Exploitation vector | Local network |
| Public exploit |
Public exploit code for vulnerability #1 is available. Vulnerability #4 is being exploited in the wild. |
| Vulnerable software |
Amazon Linux AMI Operating systems & Components / Operating system |
| Vendor | Amazon Web Services |
Security Bulletin
This security bulletin contains information about 4 vulnerabilities.
1) Race condition
EUVDB-ID: #VU6630
Risk: Low
CVSSv4.0: 2.1 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Clear]
CVE-ID: CVE-2017-2619
Exploit availability: Yes
DescriptionThe vulnerability allows a remote authenticated user to access otherwise restricted files.
The vulnerability exists due to a race condition when processing symlinks, which lead to files outside the shared folder. An attacker with ability to crate a symlink on a network share can access files not exported under the share definition.
Successful exploitation of the vulnerability may allow an attacker to gain access to potentially sensitive data, but requires that server is under heavy load.
Update the affected package to version samba-4.4.4-13.35.
Vulnerable software versionsAmazon Linux AMI: All versions
CPE2.3 External linkshttps://alas.aws.amazon.com/ALAS-2017-834.html
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.
2) Buffer overflow
EUVDB-ID: #VU6629
Risk: Medium
CVSSv4.0: 1.2 [CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID: CVE-2016-2126
CWE-ID:
CWE-119 - Memory corruption
Exploit availability: No
DescriptionThe vulnerability allows a remote authenticated attacker to escalate privileges.
The vulnerability exists due to a boundary error within Kerberos PAC validation process in winbindd. A remote authenticated attacker can send a specially crafted request to vulnerable Samba server, trigger buffer overflow and execute arbitrary code on the server with elevated privileges.
Successful exploitation of the vulnerability may allow an attacker to execute arbitrary code with elevated privileges.
Update the affected package to version samba-4.4.4-13.35.
Vulnerable software versionsAmazon Linux AMI: All versions
CPE2.3 External linkshttps://alas.aws.amazon.com/ALAS-2017-834.html
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the local network (LAN).
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
3) Improper authentication
EUVDB-ID: #VU6628
Risk: Low
CVSSv4.0: 1.3 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2016-2125
CWE-ID:
CWE-287 - Improper Authentication
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker on the local network to bypass Kerberos authentication.
The vulnerability exists due to design error when implementing Kerberos authentication. An attacker with access to local network can place a fake Samba server, intercept a valid general purpose Kerberos "Ticket Granting Ticket" (TGT) and fully impersonate the authenticated user or service.
Successful exploitation of the vulnerability may allow an attacker to bypass authentication process and gain access to otherwise restricted resources and services.
Update the affected package to version samba-4.4.4-13.35.
Vulnerable software versionsAmazon Linux AMI: All versions
CPE2.3 External linkshttps://alas.aws.amazon.com/ALAS-2017-834.html
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
4) Insecure library loading
EUVDB-ID: #VU6676
Risk: Medium
CVSSv4.0: 9.4 [CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:A/U:Green]
CVE-ID: CVE-2017-7494
CWE-ID:
CWE-426 - Untrusted Search Path
Exploit availability: Yes
DescriptionThe vulnerability allows a remote authenticated attacker to execute arbitrary code on vulnerable server.
The vulnerability exists due to insecure library loading mechanism, when processing files on file shares. A remote attacker with ability to upload file on SMB share can upload and execute arbitrary shared library on the server with privileges of the Samba process.
Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.
Update the affected package to version samba-4.4.4-13.35.
Vulnerable software versionsAmazon Linux AMI: All versions
CPE2.3 External linkshttps://alas.aws.amazon.com/ALAS-2017-834.html
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the local network (LAN).
Is there known malware, which exploits this vulnerability?
Yes. This vulnerability is being exploited in the wild.
