Ubuntu Linux 5.0/5.3 shiftfs file information disclosure

Summaryinfo

A vulnerability marked as problematic has been reported in Ubuntu Linux 5.0/5.3. This vulnerability affects unknown code of the component shiftfs. This manipulation causes file information disclosure. This vulnerability appears as CVE-2019-15793. The attack requires local access. In addition, an exploit is available.

Detailsinfo

A vulnerability classified as problematic was found in Ubuntu Linux 5.0/5.3 (Operating System). Affected by this vulnerability is an unknown code of the component shiftfs. The manipulation with an unknown input leads to a file information disclosure vulnerability. The CWE definition for the vulnerability is CWE-538. The product places sensitive information into files or directories that are accessible to actors who are allowed to have access to the files, but not to the sensitive information. As an impact it is known to affect confidentiality. The summary by CVE is:

In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, several locations which shift ids translate user/group ids before performing operations in the lower filesystem were translating them into init_user_ns, whereas they should have been translated into the s_user_ns for the lower filesystem. This resulted in using ids other than the intended ones in the lower fs, which likely did not map into the shifts s_user_ns. A local attacker could use this to possibly bypass discretionary access control permissions.

The weakness was presented 04/24/2020. This vulnerability is known as CVE-2019-15793 since 08/29/2019. An attack has to be approached locally. A single authentication is needed for exploitation. Technical details are unknown but a public exploit is available. MITRE ATT&CK project uses the attack technique T1083 for this issue.

It is possible to download the exploit at exploit-db.com. It is declared as proof-of-concept. The vulnerability scanner Nessus provides a plugin with the ID 247357 (Linux Distros Unpatched Vulnerability : CVE-2019-15793), which helps to determine the existence of the flaw in a target environment.

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 databases at Exploit-DB (47693) and Tenable (247357). See VDB-154334, VDB-154332 and VDB-154331 for similar entries. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Operating System

Vendor

• Ubuntu

Name

• Linux

Version

• 5.0
• 5.3

License

• open-source

Website

• Vendor: https://www.ubuntu.com/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion