Vulnerabilities
Misconfiguration
Compliance
CVE Vulnerabilities

CVE-2022-25235

Improper Encoding or Escaping of Output

Published: Feb 16, 2022 | Modified: May 05, 2025
CVSS 3.x
9.8
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
7.5 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
9.8 IMPORTANT
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Ubuntu
HIGH
Vulnerability-free packages from our partners
root.io logo minimus.io logo echo.ai logo
Additional information
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2022-25235
CWEhttps://cwe.mitre.org/data/definitions/116.html

xmltok_impl.c in Expat (aka libexpat) before 2.4.5 lacks certain validation of encoding, such as checks for whether a UTF-8 character is valid in a certain context.

Weakness

The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.

Affected Software

NameVendorStart VersionEnd Version
LibexpatLibexpat_project*2.4.5 (excluding)
Red Hat Enterprise Linux 6 Extended Lifecycle SupportRedHatexpat-0:2.0.1-14.el6_10*
Red Hat Enterprise Linux 7RedHatfirefox-0:91.7.0-3.el7_9*
Red Hat Enterprise Linux 7RedHatthunderbird-0:91.7.0-2.el7_9*
Red Hat Enterprise Linux 7RedHatexpat-0:2.1.0-14.el7_9*
Red Hat Enterprise Linux 8RedHatfirefox-0:91.7.0-3.el8_5*
Red Hat Enterprise Linux 8RedHatthunderbird-0:91.7.0-2.el8_5*
Red Hat Enterprise Linux 8RedHatmingw-expat-0:2.4.8-1.el8*
Red Hat Enterprise Linux 8RedHatexpat-0:2.2.5-4.el8_5.3*
Red Hat Enterprise Linux 8RedHatxmlrpc-c-0:1.51.0-5.el8_5.1*
Red Hat Enterprise Linux 8.1 Update Services for SAP SolutionsRedHatfirefox-0:91.7.0-3.el8_1*
Red Hat Enterprise Linux 8.1 Update Services for SAP SolutionsRedHatthunderbird-0:91.7.0-2.el8_1*
Red Hat Enterprise Linux 8.1 Update Services for SAP SolutionsRedHatexpat-0:2.2.5-3.el8_1.1*
Red Hat Enterprise Linux 8.1 Update Services for SAP SolutionsRedHatxmlrpc-c-0:1.51.0-5.el8_1.1*
Red Hat Enterprise Linux 8.2 Extended Update SupportRedHatfirefox-0:91.7.0-3.el8_2*
Red Hat Enterprise Linux 8.2 Extended Update SupportRedHatthunderbird-0:91.7.0-2.el8_2*
Red Hat Enterprise Linux 8.2 Extended Update SupportRedHatexpat-0:2.2.5-3.el8_2.2*
Red Hat Enterprise Linux 8.2 Extended Update SupportRedHatxmlrpc-c-0:1.51.0-5.el8_2.1*
Red Hat Enterprise Linux 8.4 Extended Update SupportRedHatfirefox-0:91.7.0-3.el8_4*
Red Hat Enterprise Linux 8.4 Extended Update SupportRedHatthunderbird-0:91.7.0-2.el8_4*
Red Hat Enterprise Linux 8.4 Extended Update SupportRedHatexpat-0:2.2.5-4.el8_4.2*
Red Hat Enterprise Linux 8.4 Extended Update SupportRedHatxmlrpc-c-0:1.51.0-5.el8_4.1*
Red Hat Enterprise Linux 9RedHatexpat-0:2.2.10-12.el9_0*
Red Hat Enterprise Linux 9RedHatexpat-0:2.2.10-12.el9_0*
Red Hat Virtualization 4 for Red Hat Enterprise Linux 7RedHatredhat-virtualization-host-0:4.3.22-20220330.1.el7_9*
Red Hat Virtualization 4 for Red Hat Enterprise Linux 8RedHatredhat-virtualization-host-0:4.4.10-202203211649_8.5*
Text-Only JBCSRedHatexpat*
Apache2Ubuntutrusty*
Apr-utilUbuntutrusty*
AyttmUbuntutrusty*
AyttmUbuntuxenial*
CableswigUbuntutrusty*
CableswigUbuntuxenial*
CadaverUbuntubionic*
CadaverUbuntufocal*
CadaverUbuntuimpish*
CadaverUbuntukinetic*
CadaverUbuntulunar*
CadaverUbuntumantic*
CadaverUbuntuoracular*
CadaverUbuntuplucky*
CadaverUbuntutrusty*
CadaverUbuntuxenial*
CmakeUbuntutrusty*
Coin3Ubuntubionic*
Coin3Ubuntutrusty*
Coin3Ubuntutrusty/esm*
Coin3Ubuntuxenial*
ExpatUbuntubionic*
ExpatUbuntudevel*
ExpatUbuntuesm-infra-legacy/trusty*
ExpatUbuntuesm-infra/bionic*
ExpatUbuntuesm-infra/focal*
ExpatUbuntuesm-infra/xenial*
ExpatUbuntufocal*
ExpatUbuntuimpish*
ExpatUbuntujammy*
ExpatUbuntukinetic*
ExpatUbuntulunar*
ExpatUbuntumantic*
ExpatUbuntunoble*
ExpatUbuntuoracular*
ExpatUbuntuplucky*
ExpatUbuntuquesting*
ExpatUbuntutrusty*
ExpatUbuntutrusty/esm*
ExpatUbuntuupstream*
ExpatUbuntuxenial*
FirefoxUbuntubionic*
FirefoxUbuntudevel*
FirefoxUbuntufocal*
FirefoxUbuntuimpish*
FirefoxUbuntujammy*
FirefoxUbuntukinetic*
FirefoxUbuntulunar*
FirefoxUbuntumantic*
FirefoxUbuntunoble*
FirefoxUbuntuoracular*
FirefoxUbuntuplucky*
FirefoxUbuntuquesting*
FirefoxUbuntutrusty*
FirefoxUbuntuxenial*
GdcmUbuntutrusty*
GhostscriptUbuntutrusty*
InsighttoolkitUbuntutrusty*
InsighttoolkitUbuntuxenial*
Insighttoolkit4Ubuntuimpish*
Insighttoolkit4Ubuntutrusty*
Insighttoolkit4Ubuntuxenial*
LibxmltokUbuntubionic*
LibxmltokUbuntuesm-apps/bionic*
LibxmltokUbuntuesm-apps/focal*
LibxmltokUbuntuesm-apps/jammy*
LibxmltokUbuntuesm-apps/noble*
LibxmltokUbuntuesm-apps/xenial*
LibxmltokUbuntufocal*
LibxmltokUbuntuhirsute*
LibxmltokUbuntuimpish*
LibxmltokUbuntujammy*
LibxmltokUbuntukinetic*
LibxmltokUbuntulunar*
LibxmltokUbuntumantic*
LibxmltokUbuntunoble*
LibxmltokUbuntuoracular*
LibxmltokUbuntuplucky*
LibxmltokUbuntutrusty*
LibxmltokUbuntuupstream*
LibxmltokUbuntuxenial*
MatanzaUbuntubionic*
MatanzaUbuntudevel*
MatanzaUbuntuesm-apps/bionic*
MatanzaUbuntuesm-apps/focal*
MatanzaUbuntuesm-apps/jammy*
MatanzaUbuntuesm-apps/noble*
MatanzaUbuntuesm-apps/xenial*
MatanzaUbuntufocal*
MatanzaUbuntuimpish*
MatanzaUbuntujammy*
MatanzaUbuntukinetic*
MatanzaUbuntulunar*
MatanzaUbuntumantic*
MatanzaUbuntunoble*
MatanzaUbuntuoracular*
MatanzaUbuntuplucky*
MatanzaUbuntuquesting*
MatanzaUbuntutrusty*
MatanzaUbuntuxenial*
SmartUbuntutrusty*
Swish-eUbuntubionic*
Swish-eUbuntufocal*
Swish-eUbuntuimpish*
Swish-eUbuntukinetic*
Swish-eUbuntulunar*
Swish-eUbuntumantic*
Swish-eUbuntuoracular*
Swish-eUbuntuplucky*
Swish-eUbuntutrusty*
Swish-eUbuntuxenial*
TdomUbuntubionic*
TdomUbuntufocal*
TdomUbuntuimpish*
TdomUbuntukinetic*
TdomUbuntulunar*
TdomUbuntumantic*
TdomUbuntuoracular*
TdomUbuntuplucky*
TdomUbuntutrusty*
TdomUbuntuxenial*
Texlive-binUbuntutrusty*
ThunderbirdUbuntubionic*
ThunderbirdUbuntudevel*
ThunderbirdUbuntufocal*
ThunderbirdUbuntuimpish*
ThunderbirdUbuntujammy*
ThunderbirdUbuntukinetic*
ThunderbirdUbuntulunar*
ThunderbirdUbuntumantic*
ThunderbirdUbuntunoble*
ThunderbirdUbuntuoracular*
ThunderbirdUbuntuplucky*
ThunderbirdUbuntuquesting*
ThunderbirdUbuntutrusty*
ThunderbirdUbuntuxenial*
Vnc4Ubuntubionic*
Vnc4Ubuntutrusty*
Vnc4Ubuntutrusty/esm*
Vnc4Ubuntuxenial*
VtkUbuntutrusty*
VtkUbuntutrusty/esm*
VtkUbuntuxenial*
Wbxml2Ubuntubionic*
Wbxml2Ubuntufocal*
Wbxml2Ubuntuimpish*
Wbxml2Ubuntukinetic*
Wbxml2Ubuntulunar*
Wbxml2Ubuntumantic*
Wbxml2Ubuntuoracular*
Wbxml2Ubuntuplucky*
Wbxml2Ubuntutrusty*
Wbxml2Ubuntuxenial*
Xmlrpc-cUbuntubionic*
Xmlrpc-cUbuntudevel*
Xmlrpc-cUbuntuesm-apps/bionic*
Xmlrpc-cUbuntuesm-apps/focal*
Xmlrpc-cUbuntuesm-apps/jammy*
Xmlrpc-cUbuntuesm-apps/noble*
Xmlrpc-cUbuntuesm-apps/xenial*
Xmlrpc-cUbuntuesm-infra-legacy/trusty*
Xmlrpc-cUbuntufocal*
Xmlrpc-cUbuntuimpish*
Xmlrpc-cUbuntujammy*
Xmlrpc-cUbuntukinetic*
Xmlrpc-cUbuntulunar*
Xmlrpc-cUbuntumantic*
Xmlrpc-cUbuntunoble*
Xmlrpc-cUbuntuoracular*
Xmlrpc-cUbuntuplucky*
Xmlrpc-cUbuntuquesting*
Xmlrpc-cUbuntutrusty*
Xmlrpc-cUbuntutrusty/esm*
Xmlrpc-cUbuntuxenial*

Extended Description

Improper encoding or escaping can allow attackers to change the commands that are sent to another component, inserting malicious commands instead. Most products follow a certain protocol that uses structured messages for communication between components, such as queries or commands. These structured messages can contain raw data interspersed with metadata or control information. For example, “GET /index.html HTTP/1.1” is a structured message containing a command (“GET”) with a single argument ("/index.html") and metadata about which protocol version is being used (“HTTP/1.1”). If an application uses attacker-supplied inputs to construct a structured message without properly encoding or escaping, then the attacker could insert special characters that will cause the data to be interpreted as control information or metadata. Consequently, the component that receives the output will perform the wrong operations, or otherwise interpret the data incorrectly.

Potential Mitigations

  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
  • For example, consider using the ESAPI Encoding control [REF-45] or a similar tool, library, or framework. These will help the programmer encode outputs in a manner less prone to error.
  • Alternately, use built-in functions, but consider using wrappers in case those functions are discovered to have a vulnerability.
  • If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
  • For example, stored procedures can enforce database query structure and reduce the likelihood of SQL injection.

References

Aqua Security is the largest pure-play cloud native security company, providing customers the freedom to innovate and run their businesses with minimal friction. The Aqua Cloud Native Security Platform provides prevention, detection, and response automation across the entire application lifecycle to secure the build, secure cloud infrastructure and secure running workloads wherever they are deployed.
Copyright © 2026 Aqua Security Software Ltd.   Privacy Policy | Terms of Use