VDB-99360 · CVE-2017-7572 · Nessus 99610

Back In Time up to 1.1.18 /proc//status authorization race condition

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.8	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as problematic, was found in Back In Time up to 1.1.18. This affects the function authorization of the file /proc/<pid>/status. The manipulation results in race condition. This vulnerability is known as CVE-2017-7572. It is possible to launch the attack remotely. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Back In Time up to 1.1.18. Affected is the function authorization of the file /proc/<pid>/status. The manipulation with an unknown input leads to a race condition vulnerability. CWE is classifying the issue as 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. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

The _checkPolkitPrivilege function in serviceHelper.py in Back In Time (aka backintime) 1.1.18 and earlier uses a deprecated polkit authorization method (unix-process) that is subject to a race condition (time of check, time of use). With this authorization method, the owner of a process requesting a polkit operation is checked by polkitd via /proc/<pid>/status, by which time the requesting process may have been replaced by a different process with the same PID that has different privileges then the original requester.

The bug was discovered 04/06/2017. The weakness was published 04/06/2017 (GitHub Repository). The advisory is shared for download at github.com. This vulnerability is traded as CVE-2017-7572 since 04/06/2017. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 99610 (Fedora 24 : backintime (2017-7c9a9b2b36)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 276579 (Fedora Security Update for backintime (FEDORA-2017-7c9a9b2b36)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 3 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (99610). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

Back In Time

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.0
VulDB Meta Temp Score: 8.4

VulDB Base Score: 9.8
VulDB Temp Score: 8.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.1
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 99610
Nessus Name: Fedora 24 : backintime (2017-7c9a9b2b36)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 867773
OpenVAS Name: Fedora Update for backintime FEDORA-2017-8dce7a3940
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Patch: github.com

Timelineinfo

04/06/2017 🔍
04/06/2017 +0 days 🔍
04/06/2017 +0 days 🔍
04/06/2017 +0 days 🔍
04/07/2017 +1 days 🔍
04/22/2017 +15 days 🔍
04/24/2017 +2 days 🔍
08/24/2024 +2678 days 🔍