Cron up to 3.0pl1-128 on Debian/Ubuntu Postinst Maintainer Script link following

CVSS Meta Temp Score
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CTI Interest Score
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6.0$0-$5k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Cron up to 3.0pl1-128 on Debian/Ubuntu. This affects an unknown part of the component Postinst Maintainer Script. Performing a manipulation results in link following. This vulnerability is known as CVE-2017-9525. Attacking locally is a requirement. No exploit is available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Cron up to 3.0pl1-128 on Debian/Ubuntu. This affects an unknown code of the component Postinst Maintainer Script. The manipulation with an unknown input leads to a link following vulnerability. CWE is classifying the issue as CWE-59. The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the cron package through 3.0pl1-128 on Debian, and through 3.0pl1-128ubuntu2 on Ubuntu, the postinst maintainer script allows for group-crontab-to-root privilege escalation via symlink attacks against unsafe usage of the chown and chmod programs.

The bug was discovered 06/09/2017. The weakness was published 06/09/2017 by Florian Weimer (Website). The advisory is shared at bugs.debian.org. This vulnerability is uniquely identified as CVE-2017-9525 since 06/09/2017. An attack has to be approached locally. A authentication is needed for exploitation. Neither technical details nor an exploit are publicly available.

The commercial vulnerability scanner Qualys is able to test this issue with plugin 176701 (Debian Security Update for cron (DLA 1723-1)).

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 107373†). Similar entries are available at VDB-131577, VDB-131578 and VDB-131579. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.0
VulDB Meta Temp Score: 6.0

VulDB Base Score: 5.3
VulDB Temp Score: 5.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.7
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Link following
CWE: CWE-59
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

06/09/2017 🔍
06/09/2017 +0 days 🔍
06/09/2017 +0 days 🔍
06/09/2017 +0 days 🔍
06/10/2017 +1 days 🔍
03/08/2019 +636 days 🔍
12/08/2022 +1371 days 🔍

Sourcesinfo

Advisory: DLA 1723-1
Researcher: Florian Weimer
Status: Confirmed

CVE: CVE-2017-9525 (🔍)
GCVE (CVE): GCVE-0-2017-9525
GCVE (VulDB): GCVE-100-102225
SecurityFocus: 107373 - Vixie Cron CVE-2019-9704 Use After Free Denial of Service Vulnerability
SecurityTracker: 1038651

See also: 🔍

Entryinfo

Created: 06/10/2017 09:05
Updated: 12/08/2022 11:07
Changes: 06/10/2017 09:05 (61), 10/16/2019 09:29 (4), 12/27/2020 07:08 (2), 12/08/2022 11:07 (2)
Complete: 🔍
Cache ID: 216::103

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

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