VDB-127467 · CVE-2018-19838 · Issue 2660

LibSass up to 3.5.4 ast.cpp clone resource consumption

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.
5.3	$0-$5k	0.00

Summaryinfo

A vulnerability marked as problematic has been reported in LibSass up to 3.5.4. Affected is the function clone of the file ast.cpp. Performing a manipulation results in resource consumption. This vulnerability is reported as CVE-2018-19838. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in LibSass up to 3.5.4 (Programming Language Software). This affects the function clone of the file ast.cpp. The manipulation with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. The summary by CVE is:

In LibSass prior to 3.5.5, functions inside ast.cpp for IMPLEMENT_AST_OPERATORS expansion allow attackers to cause a denial-of-service resulting from stack consumption via a crafted sass file, as demonstrated by recursive calls involving clone(), cloneChildren(), and copy().

The bug was discovered 06/02/2018. The weakness was disclosed 12/04/2018 (Website). It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2018-19838 since 12/03/2018. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

The vulnerability was handled as a non-public zero-day exploit for at least 185 days. During that time the estimated underground price was around $0-$5k.

Upgrading to version 3.5.5 eliminates this vulnerability.

The entries VDB-127468 and VDB-127466 are pretty similar. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Programming Language Software

Name

LibSass

Version

License

free

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔍

CVSSv2info

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💳	💳	💳	💳	💳	💳
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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: Resource consumption
CWE: CWE-400 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

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: LibSass 3.5.5

Timelineinfo

06/02/2018 🔍
12/03/2018 +184 days 🔍
12/04/2018 +1 days 🔍
12/04/2018 +0 days 🔍
12/05/2018 +1 days 🔍
06/12/2023 +1650 days 🔍

Sourcesinfo

Advisory: 2660
Status: Not defined

CVE: CVE-2018-19838 (🔍)
GCVE (CVE): GCVE-0-2018-19838
GCVE (VulDB): GCVE-100-127467
See also: 🔍

Entryinfo

Created: 12/05/2018 08:14
Updated: 06/12/2023 16:34
Changes: 12/05/2018 08:14 (60), 04/17/2020 11:08 (1), 06/12/2023 16:34 (4)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.