Vulnerability Name:

CVE-2022-2309 (CCN-230470)

Assigned:2022-06-18
Published:2022-06-18
Updated:2022-09-15
Summary:NULL Pointer Dereference allows attackers to cause a denial of service (or application crash). This only applies when lxml is used together with libxml2 2.9.10 through 2.9.14. libxml2 2.9.9 and earlier are not affected. It allows triggering crashes through forged input data, given a vulnerable code sequence in the application. The vulnerability is caused by the iterwalk function (also used by the canonicalize function). Such code shouldn't be in wide-spread use, given that parsing + iterwalk would usually be replaced with the more efficient iterparse function. However, an XML converter that serialises to C14N would also be vulnerable, for example, and there are legitimate use cases for this code sequence. If untrusted input is received (also remotely) and processed via iterwalk function, a crash can be triggered.
CVSS v3 Severity:7.5 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
6.7 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
5.3 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)
4.8 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Low
CVSS v2 Severity:5.0 Medium (CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Partial
5.0 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Partial
Vulnerability Type:CWE-476
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2022-2309

Source: XF
Type: UNKNOWN
libxml2-cve20222309-dos(230470)

Source: CCN
Type: lxml GIT Repository
Fix a crash when incorrect parser input occurs together with usages of iterwalk() on trees generated by the same parser.

Source: MISC
Type: Patch, Third Party Advisory
https://github.com/lxml/lxml/commit/86368e9cf70a0ad23cccd5ee32de847149af0c6f

Source: CONFIRM
Type: Exploit, Issue Tracking, Patch, Third Party Advisory
https://huntr.dev/bounties/8264e74f-edda-4c40-9956-49de635105ba

Source: CCN
Type: huntr Web site
NULL Pointer Dereference in function _appendStartNsEvents in lxml/lxml

Source: GENTOO
Type: UNKNOWN
GLSA-202208-06

Source: CONFIRM
Type: UNKNOWN
https://security.netapp.com/advisory/ntap-20220915-0006/

Source: CCN
Type: Mend Vulnerability Database
CVE-2022-2309

Vulnerable Configuration:Configuration 1:
  • cpe:/a:lxml:lxml:*:*:*:*:*:*:*:* (Version < 4.9.1)
  • AND
  • cpe:/a:xmlsoft:libxml2:*:*:*:*:*:*:*:* (Version >= 2.9.10 and <= 2.9.14)

  • Configuration CCN 1:
  • cpe:/a:xmlsoft:libxml2:2.9.10:-:*:*:*:*:*:*
  • OR cpe:/a:xmlsoft:libxml2:2.9.9:-:*:*:*:*:*:*

  • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:org.opensuse.security:def:118798
    P
    Security update for python-lxml (Important)
    2022-08-26
    oval:org.opensuse.security:def:119660
    P
    Security update for python-lxml (Important)
    2022-08-26
    oval:org.opensuse.security:def:118988
    P
    Security update for python-lxml (Important)
    2022-08-26
    oval:org.opensuse.security:def:119293
    P
    Security update for python-lxml (Important)
    2022-08-26
    oval:org.opensuse.security:def:119475
    P
    Security update for python-lxml (Important)
    2022-08-26
    BACK
    lxml lxml *
    xmlsoft libxml2 *
    xmlsoft libxml2 2.9.10 -
    xmlsoft libxml2 2.9.9 -