Juniper Junos OS update for OpenSSH

1) Incorrect handling of environment files

EUVDB-ID: #VU251

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2015-8325

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local user to execute arbitrary code on the target system.

The vulnerability exists in portable version of OpenSSH. A local user can execute arbitrary code as root by setting specially crafted environment variables to conduct attacks against the 'bin/login' process on systems, where PAM is configured to read user-specified environment variables and 'sshd_config' is set to 'UseLogin=yes'.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 12.3 - 17.2

External links

http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10940&cat=SIRT_1&actp=LIST

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) User enumeration via covert timing channel

EUVDB-ID: #VU255

Risk: Medium

CVSSv3.1: 4.9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:F/RL:O/RC:C]

CVE-ID: CVE-2016-6210

CWE-ID: CWE-200 - Information exposure

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to enumerate users on system.

The vulnerability exists in most systems where the Blowfish algorithm runs faster than SHA256/SHA512. A remote unauthenticated attacker can determine valid usernames by sending a specially crafted request with a large password (approximately 10,000 characters) to the target ssh daemon. On systems where a valid user's password has been hashed with SHA256/SHA512, the response time will be shorter for a non-existent username than for a valid username.

Successful exploitation of this vulnerability may result in disclosure or user logins.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 12.3 - 17.2

External links

http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10940&cat=SIRT_1&actp=LIST

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.

3) Consuming excessive CPU resources on the target system

EUVDB-ID: #VU252

Risk: Medium

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2016-6515

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to consume excessive CPU resources on the target system.

The vulnerability exists in the crypt(3) function, which accepts passwords longer that 1024 characters in auth_password() function in the auth_passwd.c . A remote unauthenticated attacker can submit a very long string as a password and consume excessive CPU resources.

Successful exploitation of this vulnerability may result in denial of service.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 12.3 - 17.2

External links

http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10940&cat=SIRT_1&actp=LIST

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, proof of concept for this vulnerability is available.

4) Use-after free

EUVDB-ID: #VU1482

Risk: Low

CVSSv3.1: 8.2 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:F/RL:O/RC:C]

CVE-ID: CVE-2015-6564

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use after free error within the mm_answer_pam_free_ctx() function in monitor.c in sshd daemon on non-OpenBSD platforms. A local unprivileged user can send an unexpected early MONITOR_REQ_PAM_FREE_CTX request and gain root privileges on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 12.3 - 17.2

External links

http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10940&cat=SIRT_1&actp=LIST

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

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.

5) Improper input validation

EUVDB-ID: #VU2015

Risk: Low

CVSSv3.1: 7.5 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2016-10009

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to execute arbitrary code on vulnerable ssh client.

The vulnerability exists due to incorrect handling of data passed to PKCS#11 module within ssh-agent. A remote attacker with control over sshd service can execute arbitrary code on vulnerable client.

Successful exploitation of this vulnerability may allow a remote attacker to execute arbitrary code on vulnerable client system but requires that client is connected to malicious SSH server.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 12.3 - 17.2

External links

http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10940&cat=SIRT_1&actp=LIST

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, proof of concept for this vulnerability is available.

6) Privilege escalation

EUVDB-ID: #VU2053

Risk: Low

CVSSv3.1: 7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2016-10010

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: Yes

Description

The vulnerability allows a local user to execute arbitrary code on vulnerable system with root privileges.

The vulnerability exists due to an error in sshd in serverloop.c, which may allow a local authenticated user to execute arbitrary code with root privileges via a forwarded Unix-domain socket.

Successful exploitation of this vulnerability may allow a local user to elevate privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 12.3 - 17.2

External links

http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10940&cat=SIRT_1&actp=LIST

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

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.

7) Information disclosure

EUVDB-ID: #VU2068

Risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-10011

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists due to an error in authfile.c, which may allow a local authenticated user to obtain host private key material.

Successful exploitation of this vulnerability may allow a local user to gain access to otherwise restricted information.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 12.3 - 17.2

External links

http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10940&cat=SIRT_1&actp=LIST

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

8) Buffer overflow

EUVDB-ID: #VU2075

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-10012

CWE-ID: CWE-119 - Memory corruption

Exploit availability: No

Description

The vulnerability allows a local user to execute arbitrary code on vulnerable system with root privileges.

The vulnerability exists in sshd due to a flaw in boundary checks in the shared memory manager that may be skipped by some optimizing compilers. A local user can trigger memory corruption and execute arbitrary code with root privileges. The issue is related to m_zback and m_zlib data structures.

Successful exploitation of this vulnerability may allow a local user to elevate privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 12.3 - 17.2

External links

http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10940&cat=SIRT_1&actp=LIST

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.