CVE-2021-43859
Denial of Service by injecting highly recursive collections or maps in XStream
Description
XStream is an open source java library to serialize objects to XML and back again. Versions prior to 1.4.19 may allow a remote attacker to allocate 100% CPU time on the target system depending on CPU type or parallel execution of such a payload resulting in a denial of service only by manipulating the processed input stream. XStream 1.4.19 monitors and accumulates the time it takes to add elements to collections and throws an exception if a set threshold is exceeded. Users are advised to upgrade as soon as possible. Users unable to upgrade may set the NO_REFERENCE mode to prevent recursion. See GHSA-rmr5-cpv2-vgjf for further details on a workaround if an upgrade is not possible.
How to fix CVE-2021-43859
To remediate CVE-2021-43859, upgrade the affected package to a fixed version below.
- —upgrade to 1.4.19 or later
Is CVE-2021-43859 being exploited?
Moderate — EPSS is 7.9%. Track this CVE but it's not at the top of the prioritisation list.
Affected packages (1)
- from 0, < 1.4.19
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |