SnakeYAML 1.18 Alias xml entity expansion

HistoryDiffrelatejsonxmlCTI

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.
7.5	$0-$5k	0.64

Summaryinfo

A vulnerability was found in SnakeYAML 1.18. It has been declared as problematic. This affects an unknown function of the component Alias Handler. Executing a manipulation can lead to xml entity expansion. The identification of this vulnerability is CVE-2017-18640. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as critical was found in SnakeYAML 1.18. This vulnerability affects some unknown processing of the component Alias Handler. The manipulation with an unknown input leads to a xml entity expansion vulnerability. The CWE definition for the vulnerability is CWE-776. The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities. As an impact it is known to affect availability. CVE summarizes:

The Alias feature in SnakeYAML 1.18 allows entity expansion during a load operation, a related issue to CVE-2003-1564.

The weakness was shared 12/12/2019. This vulnerability was named CVE-2017-18640 since 12/12/2019. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available.

The vulnerability scanner Nessus provides a plugin with the ID 276199 (TencentOS Server 3: prometheus-jmx-exporter (TSSA-2023:0146)), which helps to determine the existence of the flaw in a target environment.

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 databases at Tenable (276199) and CERT Bund (WID-SEC-2022-0770). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

IBM DB2
Red Hat Enterprise Linux
IBM SPSS
EMC Avamar
Hitachi Ops Center

Productinfo

Name

SnakeYAML

Version

1.18

CPE 2.3info

🔍

CPE 2.2info

🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.5

VulDB Base Score: 7.5
VulDB Temp Score: 7.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

NVD Base Score: 🔍

Exploitinginfo

Class: Xml entity expansion
CWE: CWE-776
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

Nessus ID: 276199
Nessus Name: TencentOS Server 3: prometheus-jmx-exporter (TSSA-2023:0146)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

12/12/2019 🔍
12/12/2019 +0 days 🔍
12/12/2019 +0 days 🔍
01/11/2026 +2222 days 🔍

Sourcesinfo

Advisory: 377
Status: Not defined

CVE: CVE-2017-18640 (🔍)
GCVE (CVE): GCVE-0-2017-18640
GCVE (VulDB): GCVE-100-147034
CERT Bund: WID-SEC-2022-0770 - IBM DB2: Mehrere Schwachstellen

Entryinfo

Created: 12/12/2019 10:51
Updated: 01/11/2026 14:34
Changes: 12/12/2019 10:51 (34), 12/12/2019 10:56 (17), 03/10/2024 15:04 (4), 03/10/2024 15:08 (1), 11/24/2025 06:38 (17), 01/11/2026 14:34 (7)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.