QID 353077

Date Published: 2021-12-10

QID 353077: Amazon Linux Security Advisory for xstream : ALAS2-2021-1729

a flaw was found in xstream, a simple library used to serialize objects to xml and back again.
This flaw allows a remote attacker to load and execute arbitrary code from a remote host by manipulating the processed input stream.
The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. (
( CVE-2021-39139) xstream is a simple library to serialize objects to xml and back again.
In affected versions this vulnerability 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.
No user is affected, who followed the recommendation to setup xstreams security framework with a whitelist limited to the minimal required types.
Xstream 1.4.18 uses no longer a blacklist by default, since it cannot be secured for general purpose. (
( CVE-2021-39140) a flaw was found in xstream, a simple library used to serialize objects to xml and back again.
( CVE-2021-39141) (cve-2021-39144) (cve-2021-39145) (cve-2021-39146) (cve-2021-39147) (cve-2021-39148) (cve-2021-39149) (cve-2021-39151) (cve-2021-39153) (cve-2021-39154) a flaw was found in xstream, a simple library used to serialize objects to xml and back again.
This flaw allows a remote attacker to request data from internal resources that are not publicly available by manipulating the processed input stream with java runtime versions 14 to 8.
( CVE-2021-39150) (cve-2021-39152)



Note: The preceding description block is extracted directly from the security advisory. Using automation, we have attempted to clean and format it as much as possible without introducing additional issues.

Successful exploitation of this vulnerability could lead to a securitybreach or could affect integrity, availability, and confidentiality.

  • CVSS V3 rated as Critical - 8.8 severity.
  • CVSS V2 rated as High - 6.5 severity.
  • Solution
    Please refer to Amazon advisory: ALAS2-2021-1729 for affected packages and patching details, or update with your package manager.
    Vendor References
    Software Advisories
    Advisory ID Software Component Link
    ALAS2-2021-1729 Amazon Linux 2 URL Logo alas.aws.amazon.com/AL2/ALAS-2021-1729.html