Apport on Ubuntu Crash Report Symlink toctou

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5.4	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Apport on Ubuntu. It has been declared as problematic. This affects an unknown function of the component Crash Report Handler. The manipulation as part of Symlink results in toctou. This vulnerability is reported as CVE-2020-8833. The attack requires a local approach. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Apport on Ubuntu. Affected is some unknown processing of the component Crash Report Handler. The manipulation as part of a Symlink leads to a toctou vulnerability. CWE is classifying the issue as CWE-367. The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Time-of-check Time-of-use Race Condition vulnerability on crash report ownership change in Apport allows for a possible privilege escalation opportunity. If fs.protected_symlinks is disabled, this can be exploited between the os.open and os.chown calls when the Apport cron script clears out crash files of size 0. A symlink with the same name as the deleted file can then be created upon which chown will be called, changing the file owner to root. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22.

The weakness was disclosed 04/22/2020 (Website). The advisory is shared for download at bugs.launchpad.net. This vulnerability is traded as CVE-2020-8833 since 02/10/2020. The exploitability is told to be difficult. The attack needs to be approached locally. Required for exploitation is a authentication. There are neither technical details nor an exploit publicly available.

Upgrading to version 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 or 2.20.11-0ubuntu22 eliminates this vulnerability.

The entry VDB-154271 is pretty similar. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

Apport

License

free

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.6
NVD Vector: 🔍

CNA Base Score: 5.6
CNA Vector (Canonical Ltd.): 🔍

CVSSv2info

AV	AC	Au	C	I	A
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Toctou
CWE: CWE-367 / CWE-362
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Apport 2.20.1-0ubuntu2.23/2.20.9-0ubuntu7.14/2.20.11-0ubuntu8.8/2.20.11-0ubuntu22

Timelineinfo

02/10/2020 🔍
04/22/2020 +72 days 🔍
04/23/2020 +1 days 🔍
06/02/2024 +1501 days 🔍

Sourcesinfo

Advisory: USN-4315-2
Status: Not defined
Confirmation: 🔍

CVE: CVE-2020-8833 (🔍)
GCVE (CVE): GCVE-0-2020-8833
GCVE (VulDB): GCVE-100-154272
See also: 🔍

Entryinfo

Created: 04/23/2020 11:52
Updated: 06/02/2024 08:51
Changes: 04/23/2020 11:52 (40), 04/23/2020 11:57 (11), 10/11/2020 19:40 (1), 10/11/2020 19:49 (1), 06/02/2024 08:48 (17), 06/02/2024 08:51 (18)
Complete: 🔍
Cache ID: 216::103

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