Remote command execution via manipulated unmarshalling stream
Published Mar 22, 2021 · Updated Aug 3, 2024
Remote command execution in XStream through 1.4.15 allows remote attackers with sufficient rights to execute host commands via crafted XML unmarshalling input. During unmarshalling, type information in the stream lets XStream instantiate attacker-selected classes, including a PriorityQueue payload that triggers command execution. The attack requires access to an application that unmarshals attacker-controlled streams; a strict whitelist prevents the vulnerable path, while default blacklist configurations remain exposed.
Summary
What happened
Remote command execution in XStream through 1.4.15 allows remote attackers with sufficient rights to execute host commands via crafted XML unmarshalling input. During unmarshalling, type information in the stream lets XStream instantiate attacker-selected classes, including a PriorityQueue payload that triggers command execution. The attack requires access to an application that unmarshals attacker-controlled streams; a strict whitelist prevents the vulnerable path, while default blacklist configurations remain exposed.
The record
- CVE
- CVE-2021-21345
- Published
- Mar 22, 2021
- Updated
- Aug 3, 2024
- Vendor
- XStream
- Product
- XStream
- Classifications
- CWE-78, T1203
- Attack vector
- network
- Privileges
- authenticated
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
Compare your product and version with the public record. A matching version still requires validation against your environment.
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?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo