Arbitrary file deletion via injected object graph
Published Mar 22, 2021 · Updated Aug 3, 2024
Deserialization flaws in XStream before 1.4.16 allow remote attackers to delete arbitrary files through crafted serialized input. During unmarshalling, attacker-supplied type metadata makes XStream instantiate a PriorityQueue gadget chain whose FileInputStream-backed Unix pipe unlinks a chosen path. The attack requires an application to accept untrusted serialized data, a default blacklist rather than a restrictive whitelist, and process permission to delete the target file.
Summary
What happened
Deserialization flaws in XStream before 1.4.16 allow remote attackers to delete arbitrary files through crafted serialized input. During unmarshalling, attacker-supplied type metadata makes XStream instantiate a PriorityQueue gadget chain whose FileInputStream-backed Unix pipe unlinks a chosen path. The attack requires an application to accept untrusted serialized data, a default blacklist rather than a restrictive whitelist, and process permission to delete the target file.
The record
- CVE
- CVE-2021-21343
- Published
- Mar 22, 2021
- Updated
- Aug 3, 2024
- Vendor
- XStream
- Product
- XStream
- Classifications
- CWE-502, CWE-73, T1485
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 22, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.4.16
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- XStream arbitrary-file-deletion reproduction payloadproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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