lftp up to 4.8.3 File Name input validation

Summaryinfo

A vulnerability, which was classified as critical, was found in lftp up to 4.8.3. This vulnerability affects unknown code of the component File Name Handler. Executing a manipulation can lead to input validation. This vulnerability appears as CVE-2018-10916. The attack may be performed from remote. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in lftp up to 4.8.3. It has been declared as critical. This vulnerability affects some unknown functionality of the component File Name Handler. The manipulation with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect integrity, and availability. CVE summarizes:

It has been discovered that lftp up to and including version 4.8.3 does not properly sanitize remote file names, leading to a loss of integrity on the local system when reverse mirroring is used. A remote attacker may trick a user to use reverse mirroring on an attacker controlled FTP server, resulting in the removal of all files in the current working directory of the victim's system.

The bug was discovered 05/16/2018. The weakness was presented 08/01/2018 as not defined bug report (Bugzilla). The advisory is shared for download at bugzilla.redhat.com. This vulnerability was named CVE-2018-10916 since 05/09/2018. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 77 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 111524 (Slackware 14.0 / 14.1 / 14.2 / current : lftp (SSA:2018-214-01)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Slackware Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 172238 (OpenSUSE Security Update for lftp (openSUSE-SU-2019:1110-1)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 2 days after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (111524). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

• lftp

Version

• 4.8.0
• 4.8.1
• 4.8.2
• 4.8.3

License

• open-source

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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