CVE-2020-9484
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 55.5% chance of exploitation in the next 30 days (EPSS). Higher than most.
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 55.5% in the next 30 days (EPSS).
- Severity: 7.0 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 55.5% · EPSS, next 30 days
- Weakness
- CWE-502 · Unsafe deserialization
- Record status
- Modified
Affected
- Apache Tomcat < 7.0.108
- Apache Tomcat < 8.5.63
- Apache Tomcat < 9.0.43
- Apache Tomcat 9.0.0
- Apache Tomcat 10.0.0
- Debian Linux 8.0
- Debian Linux 9.0
- Debian Linux 10.0
Attack profile CVSS 3.1 · 7.0
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2020-9484.md and follow it. Check whether this project is affected by CVE-2020-9484. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://lists.apache.org/thread.html/r77eae567ed829da9012cadb29af17f2df8fa23bf66faf88229857bb1%40%3Cannounce.tomcat.apache.org%3E
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://www.oracle.com/security-alerts/cpujan2021.html
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpujul2020.html
- https://www.oracle.com/security-alerts/cpuoct2020.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://lists.apache.org/thread.html/r77eae567ed829da9012cadb29af17f2df8fa23bf66faf88229857bb1%40%3Cannounce.tomcat.apache.org%3E
- https://www.oracle.com//security-alerts/cpujul2021.html
References
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00057.html
- http://packetstormsecurity.com/files/157924/Apache-Tomcat-CVE-2020-9484-Proof-Of-Concept.html
- http://seclists.org/fulldisclosure/2020/Jun/6
- http://www.openwall.com/lists/oss-security/2021/03/01/2
- https://kc.mcafee.com/corporate/index?page=content&id=SB10332
- https://lists.apache.org/thread.html/r11ce01e8a4c7269b88f88212f21830edf73558997ac7744f37769b77%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r123b3ebe389f46f9d337923f393cdae4d3e9b78d982d706712f0898c%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/r26950738f4b4ca2d256597cf391d52d3450fa665c297ea5ca38f5469%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r77eae567ed829da9012cadb29af17f2df8fa23bf66faf88229857bb1%40%3Cannounce.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r7bc247fffcb1d58415215c861d2354bd653c86266230d78a93c71ae2%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r8a2ac0e476dbfc1e6440b09dcc782d444ad635d6da26f0284725a5dc%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/r8dd19c514face6dd85fd4eab0271854883f40c7307926c1f7cd5400c%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/raa4123e472175bb052fbba165d37187cea923f755e8f3f30d124cb3f%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rb1c0fb105ce2b93b7ec6fc1b77dd208022621a91c12d1f580813cfed%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rb51ccd58b2152fc75125b2406fc93e04ca9d34e737263faa6ff0f41f%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rc1778b38e74b5b6142414d57623bd55b023a72361f422836782fca3c%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rc8473b08abdf3c16494ed817bec1717a0ee0c8080315bc27db5f21c3%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rf59c72572b9fee674a5d5cc6afeca4ffc3918a02c354a81cc50b7119%40%3Ccommits.tomee.apache.org%3E
- https://lists.apache.org/thread.html/rf6d5d57b114678d8898005faef31e9fd6d7c981fcc4ccfc3bc272fc9%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rf70f53af27e04869bdac18b1fc14a3ee529e59eb12292c8791a77926%40%3Cusers.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rfe62fbf9d4c314f166fe8c668e50e5d9dd882a99447f26f0367474bf%40%3Cannounce.apache.org%3E
- https://lists.apache.org/thread.html/rfe62fbf9d4c314f166fe8c668e50e5d9dd882a99447f26f0367474bf%40%3Cannounce.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rfe62fbf9d4c314f166fe8c668e50e5d9dd882a99447f26f0367474bf%40%3Cdev.tomcat.apache.org%3E
- https://lists.apache.org/thread.html/rfe62fbf9d4c314f166fe8c668e50e5d9dd882a99447f26f0367474bf%40%3Cusers.tomcat.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2020/05/msg00020.html