Multiple vulnerabilities in Cisco IOS and IOS XE

Published: 2019-01-10 | Updated: 2019-01-10

Risk	Low
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2018-0282 CVE-2018-0484
CWE-ID	CWE-20 CWE-119
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	Cisco IOS/IOS XE Operating systems & Components / Operating system Cisco IOS Operating systems & Components / Operating system
Vendor	Cisco Systems, Inc

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Improper input validation

EUVDB-ID: #VU16927

Risk: Low

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2018-0282

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition.

The vulnerability exists in the TCP socket code due to a state condition between the socket state and the transmission control block (TCB) state. A remote attacker can send specific HTTP requests at a sustained rate to a reachable IP address of the affected software and cause the affected device to reload, resulting in a denial of service (DoS) condition on an affected device.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Cisco IOS/IOS XE: 15.2.2 E4

CPE2.3

cpe:2.3:o:cisco_systems:cisco_ios_ios_xe:15.2.2 E4:*:*:*:*:*:*:*

External links

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190109-tcp

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) Security restrictions bypass

EUVDB-ID: #VU16928

Risk: Low

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2018-0484

CWE-ID: CWE-119 - Memory corruption

Exploit availability: No

Description

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

The vulnerability exists in the access control logic of the Secure Shell (SSH) server due to a missing check in the SSH server. A remote unauthenticated attacker can open an SSH connection to an affected Cisco IOS or IOS XE device with a source address belonging to a VRF instance and forward the instance despite the absence of the vrf-also keyword in the access-class configuration.