Apache Tomcat up to 7.0.99/8.5.50/9.0.30 Header Parsing HTTP Request request smuggling

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.1$5k-$25k0.00

Summaryinfo

A vulnerability was found in Apache Tomcat up to 7.0.99/8.5.50/9.0.30. It has been declared as critical. The affected element is an unknown function of the component Header Parsing. Such manipulation as part of HTTP Request leads to request smuggling. This vulnerability is traded as CVE-2020-1935. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Apache Tomcat up to 7.0.99/8.5.50/9.0.30 (Application Server Software). Affected by this issue is some unknown processing of the component Header Parsing. The manipulation as part of a HTTP Request leads to a request smuggling vulnerability. Using CWE to declare the problem leads to CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In Apache Tomcat 9.0.0.M1 to 9.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99 the HTTP header parsing code used an approach to end-of-line parsing that allowed some invalid HTTP headers to be parsed as valid. This led to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely.

The weakness was shared 02/24/2020 (Website). The advisory is shared for download at lists.apache.org. This vulnerability is handled as CVE-2020-1935 since 12/02/2019. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 08/11/2025).

The vulnerability scanner Nessus provides a plugin with the ID 247395 (Linux Distros Unpatched Vulnerability : CVE-2020-1935), 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 vulnerability database at Tenable (247395). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

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Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.1
VulDB Meta Temp Score: 6.1

VulDB Base Score: 7.3
VulDB Temp Score: 7.3
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.8
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Request smuggling
CWE: CWE-444
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: 247395
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2020-1935

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

12/02/2019 🔍
02/24/2020 +84 days 🔍
02/25/2020 +1 days 🔍
08/11/2025 +1993 days 🔍

Sourcesinfo

Vendor: apache.org

Advisory: USN-4448-1
Status: Not defined

CVE: CVE-2020-1935 (🔍)
GCVE (CVE): GCVE-0-2020-1935
GCVE (VulDB): GCVE-100-150464

Entryinfo

Created: 02/25/2020 09:36
Updated: 08/11/2025 00:07
Changes: 02/25/2020 09:36 (39), 02/25/2020 09:41 (18), 04/02/2024 14:36 (17), 08/11/2025 00:07 (2)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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