Security Bulletin: XStream (Publicly disclosed vulnerability)

Summary

XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.16, there is a vulnerability where the processed stream at unmarshalling time contains type information to recreate the formerly written objects. XStream creates therefore new instances based on these type information. An attacker can manipulate the processed input stream and replace or inject objects, that result in a server-side forgery request. No user is affected, who followed the recommendation to setup XStream’s security framework with a allowlist limited to the minimal required types. If you rely on XStream’s default blocklist of the Security Framework, you will have to use at least version 1.4.16.

Vulnerability Details

CVEID:CVE-2021-21342
**DESCRIPTION:**XStream is vulnerable to server-side request forgery, caused by a flaw when processing stream at unmarshalling time. By manipulating the processed input stream and replace or inject objects, an attacker could exploit this vulnerability to conduct SSRF attack o access data streams from an arbitrary URL referencing a resource in an intranet or the local host.
CVSS Base score: 7.4
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198619 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N)

CVEID:CVE-2021-21350
**DESCRIPTION:**XStream could allow a remote attacker to execute arbitrary code on the system, caused by a flaw when processing stream at unmarshalling time. By manipulating the processed input stream and replace or inject objects, an attacker could exploit this vulnerability to execute arbitrary code on the system.
CVSS Base score: 8.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198627 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)

CVEID:CVE-2021-21346
**DESCRIPTION:**XStream could allow a remote attacker to execute arbitrary code on the system, caused by a flaw when processing stream at unmarshalling time. By manipulating the processed input stream and replace or inject objects, an attacker could exploit this vulnerability to execute arbitrary code on the system.
CVSS Base score: 7.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198623 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H)

CVEID:CVE-2021-21349
**DESCRIPTION:**XStream is vulnerable to server-side request forgery, caused by a flaw when processing stream at unmarshalling time. By manipulating the processed input stream and replace or inject objects, an attacker could exploit this vulnerability to conduct SSRF attack to access data streams from an arbitrary URL referencing a resource in an intranet or the local host.
CVSS Base score: 8.7
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198626 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N)

CVEID:CVE-2021-21341
**DESCRIPTION:**XStream is vulnerable to a denial of service, caused by an endless loop flaw when processing stream at unmarshalling time. By manipulating the processed input stream, a remote attacker could exploit this vulnerability to allocate 100% CPU time.
CVSS Base score: 7.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198618 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:CVE-2021-21345
**DESCRIPTION:**XStream could allow a remote authenticated attacker to execute arbitrary commands on the system, caused by a flaw when processing stream at unmarshalling time. By manipulating the processed input stream and replace or inject objects, an attacker could exploit this vulnerability to execute arbitrary commands on the system.
CVSS Base score: 8.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198622 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H)

CVEID:CVE-2021-21348
**DESCRIPTION:**XStream is vulnerable to a denial of service, caused by a regular expression denial of service flaw (ReDos). By using a specially-crafted regular expression input, a remote attacker could exploit this vulnerability to consume maximum CPU time.
CVSS Base score: 5.9
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198625 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:CVE-2021-21344
**DESCRIPTION:**XStream could allow a remote attacker to execute arbitrary code on the system, caused by a flaw when processing stream at unmarshalling time. By manipulating the processed input stream and replace or inject objects, an attacker could exploit this vulnerability to execute arbitrary code from a remote server.
CVSS Base score: 9.8
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198621 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

CVEID:CVE-2021-21347
**DESCRIPTION:**XStream could allow a remote attacker to execute arbitrary code on the system, caused by a flaw when processing stream at unmarshalling time. By manipulating the processed input stream and replace or inject objects, an attacker could exploit this vulnerability to execute arbitrary code on the system.
CVSS Base score: 8.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198624 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)

CVEID:CVE-2021-21343
**DESCRIPTION:**XStream could allow a remote attacker to bypass security restrictions, caused by a flaw when processing stream at unmarshalling time. By manipulating the processed input stream and replace or inject objects, an attacker could exploit this vulnerability to delete arbitrary files on the system.
CVSS Base score: 5.3
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198620 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N)

CVEID:CVE-2021-21351
**DESCRIPTION:**XStream could allow a remote attacker to execute arbitrary code on the system, caused by a flaw when processing stream at unmarshalling time. By manipulating the processed input stream and replace or inject objects, an attacker could exploit this vulnerability to execute arbitrary code on the system.
CVSS Base score: 8.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198628 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)

Affected Products and Versions

Remediation/Fixes

ITNCM 6.4.2 Fix Pack 14 can be downloaded from Fix Central

Workarounds and Mitigations

None