Cisco Firepower System Software up to 6.2.3 Server Message Block protection mechanism

Summaryinfo

A vulnerability was found in Cisco Firepower System Software up to 6.2.3 and classified as critical. Affected by this issue is some unknown functionality of the component Server Message Block. Such manipulation leads to protection mechanism. This vulnerability is documented as CVE-2018-0243. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Cisco Firepower System Software up to 6.2.3 (Firewall Software). Affected by this issue is an unknown code of the component Server Message Block. The manipulation with an unknown input leads to a protection mechanism vulnerability. Using CWE to declare the problem leads to CWE-693. The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product. Impacted is confidentiality, integrity, and availability. CVE summarizes:

A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass a configured file action policy that is intended to drop the Server Message Block Version 2 (SMB2) and SMB Version 3 (SMB3) protocols if malware is detected. The vulnerability is due to incorrect detection of an SMB2 or SMB3 file based on the total file length. An attacker could exploit this vulnerability by sending a crafted SMB2 or SMB3 transfer request through the targeted device. An exploit could allow the attacker to pass SMB2 or SMB3 files that could be malware even though the device is configured to block them. This vulnerability does not exist for SMB Version 1 (SMB1) files. This vulnerability affects Cisco Firepower System Software when one or more file action policies are configured, on software releases prior to 6.2.3. Cisco Bug IDs: CSCvg68807.

The bug was discovered 04/18/2018. The weakness was released 04/19/2018 with Cisco (Website). The advisory is shared for download at securityfocus.com. This vulnerability is handled as CVE-2018-0243 since 11/27/2017. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 01/30/2020).

The vulnerability was handled as a non-public zero-day exploit for at least 1 days. During that time the estimated underground price was around $5k-$25k.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at SecurityFocus (BID 103943†). Entries connected to this vulnerability are available at VDB-116879 and VDB-116877. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Firewall Software

Vendor

• Cisco

Name

• Firepower System Software

Version

• 6.2.0
• 6.2.1
• 6.2.2
• 6.2.3

License

• commercial

Website

• Vendor: https://www.cisco.com/

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Once again VulDB remains the best source for vulnerability data.

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