Two backdoors in Juniper ScreenOS

Published: 2015-12-17 | Updated: 2017-03-24
Severity Critical
Patch available YES
Number of vulnerabilities 2
CVE ID CVE-2015-7755
CVE-2015-7756
CWE ID CWE-287
CWE-327
Exploitation vector Network
Public exploit Vulnerability #1 is being exploited in the wild.
Vulnerability #2 is being exploited in the wild.
Vulnerable software Juniper ScreenOS Subscribe
Vendor Juniper Networks, Inc.

Security Advisory

1) Authentication bypass

Severity: Critical

CVSSv3: 8.2 [CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C] [PCI]

CVE-ID: CVE-2015-7755

CWE-ID: CWE-287 - Improper Authentication

Description

The vulnerability allows a remote attacker to bypass authentication on the target system.

The weakness exists due to presence of backdoor in Juniper ScreenOS code. A remote attacker can enter a password "<<< %s(un='%s') = %u" during a SSH or TELNET session and obtain administrative access to the device.

Successful exploitation of the vulnerability results in unauthorized access to the vulnerable system.

Note: the vulnerability was being actively exploited.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Juniper ScreenOS: 6.3.0r17, 6.3.0r18, 6.3.0r19, 6.3.0r20

CPE External links

http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10713

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. However, a fully functional exploit for this vulnerability is available.

2) Information disclosure

Severity: High

CVSSv3: 4.9 [CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:F/RL:O/RC:C] [PCI]

CVE-ID: CVE-2015-7756

CWE-ID: CWE-327 - Use of a Broken or Risky Cryptographic Algorithm

Description

The vulnerability allows a remote attacker to obtain potentially sensitive information on the target system.

The weakness exists due to usage of insecure encryption keys. A remote attacker can with ability to monitor VPN traffic can intercept and decrypt it.

Successful exploitation of the vulnerability results in information disclosure on the target system.

Note: the vulnerability was disclosed as part of two backdoors during internal source code audit.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Juniper ScreenOS: 6.2.0r15, 6.2.0r16, 6.2.0r17, 6.2.0r18, 6.3.0r12, 6.3.0r13, 6.3.0r14, 6.3.0r15, 6.3.0r16, 6.3.0r17, 6.3.0r18, 6.3.0r19, 6.3.0r20

CPE External links

https://kb.juniper.net/InfoCenter/index?page=content&id=JSA10713&actp=search

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. However, a fully functional exploit for this vulnerability is available.