Apport Symlink ~/.apport-ignore.xml race condition

Summaryinfo

A vulnerability identified as problematic has been detected in Apport. This impacts an unknown function of the file ~/.apport-ignore.xml of the component Symlink Handler. This manipulation causes race condition. This vulnerability appears as CVE-2019-7307. The attack requires local access. In addition, an exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Apport. It has been declared as problematic. Affected by this vulnerability is some unknown functionality of the file ~/.apport-ignore.xml of the component Symlink Handler. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Apport before versions 2.14.1-0ubuntu3.29+esm1, 2.20.1-0ubuntu2.19, 2.20.9-0ubuntu7.7, 2.20.10-0ubuntu27.1, 2.20.11-0ubuntu5 contained a TOCTTOU vulnerability when reading the users ~/.apport-ignore.xml file, which allows a local attacker to replace this file with a symlink to any other file on the system and so cause Apport to include the contents of this other file in the resulting crash report. The crash report could then be read by that user either by causing it to be uploaded and reported to Launchpad, or by leveraging some other vulnerability to read the resulting crash report, and so allow the user to read arbitrary files on the system.

The weakness was presented 08/29/2019. This vulnerability is known as CVE-2019-7307 since 02/01/2019. An attack has to be approached locally. The exploitation doesn't need any form of authentication. Technical details and also a public exploit are known.

It is possible to download the exploit at packetstormsecurity.com. It is declared as proof-of-concept. By approaching the search of inurl:~/.apport-ignore.xml it is possible to find vulnerable targets with Google Hacking.

Upgrading to version 2.14.1-0ubuntu3.29+esm1, 2.20.1-0ubuntu2.19, 2.20.9-0ubuntu7.7, 2.20.10-0ubuntu27.1 or 2.20.11-0ubuntu5 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• Apport

License

• free

CPE 2.3info

• 🔍

CPE 2.2info

• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion