Apache Tomcat up to 7.0.103/8.5.54/9.0.34/10.0.0-M4 deserialization

Summaryinfo

A vulnerability classified as critical was found in Apache Tomcat up to 7.0.103/8.5.54/9.0.34/10.0.0-M4. Affected is an unknown function. The manipulation results in deserialization. This vulnerability is cataloged as CVE-2020-9484. The attack may be launched remotely. Furthermore, there is an exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical has been found in Apache Tomcat up to 7.0.103/8.5.54/9.0.34/10.0.0-M4 (Application Server Software). Affected is an unknown function. The manipulation with an unknown input leads to a deserialization vulnerability. CWE is classifying the issue as CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

When using Apache Tomcat versions 10.0.0-M1 to 10.0.0-M4, 9.0.0.M1 to 9.0.34, 8.5.0 to 8.5.54 and 7.0.0 to 7.0.103 if a) an attacker is able to control the contents and name of a file on the server; and b) the server is configured to use the PersistenceManager with a FileStore; and c) the PersistenceManager is configured with sessionAttributeValueClassNameFilter="null" (the default unless a SecurityManager is used) or a sufficiently lax filter to allow the attacker provided object to be deserialized; and d) the attacker knows the relative file path from the storage location used by FileStore to the file the attacker has control over; then, using a specifically crafted request, the attacker will be able to trigger remote code execution via deserialization of the file under their control. Note that all of conditions a) to d) must be true for the attack to succeed.

The weakness was shared 05/20/2020. This vulnerability is traded as CVE-2020-9484 since 03/01/2020. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are unknown but a public exploit is available.

A public exploit has been developed by masahiro331 in JHTML/JSP and been published 1 days after the advisory. The exploit is shared for download at github.com. It is declared as proof-of-concept. As 0-day the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 208555 (CentOS 6 : tomcat6 (RHSA-2020:2529)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (208555). The entry VDB-158169 is related to this item. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Application Server Software

Vendor

• Apache

Name

• Tomcat

Version

• 7.0.103
• 8.5.0
• 8.5.1
• 8.5.2
• 8.5.3
• 8.5.4
• 8.5.5
• 8.5.6
• 8.5.7
• 8.5.8
• 8.5.9
• 8.5.10
• 8.5.11
• 8.5.12
• 8.5.13
• 8.5.14
• 8.5.15
• 8.5.16
• 8.5.17
• 8.5.18
• 8.5.19
• 8.5.20
• 8.5.21
• 8.5.22
• 8.5.23
• 8.5.24
• 8.5.25
• 8.5.26
• 8.5.27
• 8.5.28
• 8.5.29
• 8.5.30
• 8.5.31
• 8.5.32
• 8.5.33
• 8.5.34
• 8.5.35
• 8.5.36
• 8.5.37
• 8.5.38
• 8.5.39
• 8.5.40
• 8.5.41
• 8.5.42
• 8.5.43
• 8.5.44
• 8.5.45
• 8.5.46
• 8.5.47
• 8.5.48
• 8.5.49
• 8.5.50
• 8.5.51
• 8.5.52
• 8.5.53
• 8.5.54
• 9.0.0
• 9.0.1
• 9.0.2
• 9.0.3
• 9.0.4
• 9.0.5
• 9.0.6
• 9.0.7
• 9.0.8
• 9.0.9
• 9.0.10
• 9.0.11
• 9.0.12
• 9.0.13
• 9.0.14
• 9.0.15
• 9.0.16
• 9.0.17
• 9.0.18
• 9.0.19
• 9.0.20
• 9.0.21
• 9.0.22
• 9.0.23
• 9.0.24
• 9.0.25
• 9.0.26
• 9.0.27
• 9.0.28
• 9.0.29
• 9.0.30
• 9.0.31
• 9.0.32
• 9.0.33
• 9.0.34
• 10.0.0-M4

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

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Exploitinginfo

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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