UBUNTU-CVE-2021-28957

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Source
https://ubuntu.com/security/CVE-2021-28957
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-28957.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2021-28957
Upstream
Downstream
Related
Published
2021-03-21T05:15:00Z
Modified
2025-07-16T08:26:18.063746Z
Severity
  • 6.1 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

An XSS vulnerability was discovered in python-lxml's clean module versions before 4.6.3. When disabling the safeattrsonly and forms arguments, the Cleaner class does not remove the formaction attribute allowing for JS to bypass the sanitizer. A remote attacker could exploit this flaw to run arbitrary JS code on users who interact with incorrectly sanitized HTML. This issue is patched in lxml 4.6.3.

References

Affected packages

Ubuntu:Pro:14.04:LTS / lxml

Package

Name
lxml
Purl
pkg:deb/ubuntu/lxml@3.3.3-1ubuntu0.2+esm3?arch=source&distro=trusty/esm

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.3.3-1ubuntu0.2+esm3

Affected versions

3.*

3.2.0-1
3.3.0~beta2-1
3.3.0~beta4-1
3.3.1-1
3.3.2-1
3.3.2-1build1
3.3.3-1
3.3.3-1ubuntu0.1
3.3.3-1ubuntu0.2
3.3.3-1ubuntu0.2+esm1
3.3.3-1ubuntu0.2+esm2

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "python-lxml",
            "binary_version": "3.3.3-1ubuntu0.2+esm3"
        },
        {
            "binary_name": "python-lxml-dbg",
            "binary_version": "3.3.3-1ubuntu0.2+esm3"
        },
        {
            "binary_name": "python-lxml-dbgsym",
            "binary_version": "3.3.3-1ubuntu0.2+esm3"
        },
        {
            "binary_name": "python-lxml-doc",
            "binary_version": "3.3.3-1ubuntu0.2+esm3"
        },
        {
            "binary_name": "python3-lxml",
            "binary_version": "3.3.3-1ubuntu0.2+esm3"
        },
        {
            "binary_name": "python3-lxml-dbg",
            "binary_version": "3.3.3-1ubuntu0.2+esm3"
        },
        {
            "binary_name": "python3-lxml-dbgsym",
            "binary_version": "3.3.3-1ubuntu0.2+esm3"
        }
    ]
}

Ubuntu:16.04:LTS / lxml

Package

Name
lxml
Purl
pkg:deb/ubuntu/lxml@3.5.0-1ubuntu0.4?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.5.0-1ubuntu0.4

Affected versions

3.*

3.4.4-1
3.5.0-1
3.5.0-1build1
3.5.0-1ubuntu0.1
3.5.0-1ubuntu0.2
3.5.0-1ubuntu0.3

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "python-lxml",
            "binary_version": "3.5.0-1ubuntu0.4"
        },
        {
            "binary_name": "python-lxml-dbg",
            "binary_version": "3.5.0-1ubuntu0.4"
        },
        {
            "binary_name": "python-lxml-doc",
            "binary_version": "3.5.0-1ubuntu0.4"
        },
        {
            "binary_name": "python3-lxml",
            "binary_version": "3.5.0-1ubuntu0.4"
        },
        {
            "binary_name": "python3-lxml-dbg",
            "binary_version": "3.5.0-1ubuntu0.4"
        }
    ]
}

Ubuntu:18.04:LTS / lxml

Package

Name
lxml
Purl
pkg:deb/ubuntu/lxml@4.2.1-1ubuntu0.4?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
4.2.1-1ubuntu0.4

Affected versions

4.*

4.0.0-1
4.1.0-1
4.2.0-1
4.2.1-1
4.2.1-1ubuntu0.1
4.2.1-1ubuntu0.2
4.2.1-1ubuntu0.3

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "python-lxml",
            "binary_version": "4.2.1-1ubuntu0.4"
        },
        {
            "binary_name": "python-lxml-dbg",
            "binary_version": "4.2.1-1ubuntu0.4"
        },
        {
            "binary_name": "python-lxml-doc",
            "binary_version": "4.2.1-1ubuntu0.4"
        },
        {
            "binary_name": "python3-lxml",
            "binary_version": "4.2.1-1ubuntu0.4"
        },
        {
            "binary_name": "python3-lxml-dbg",
            "binary_version": "4.2.1-1ubuntu0.4"
        }
    ]
}

Ubuntu:20.04:LTS / lxml

Package

Name
lxml
Purl
pkg:deb/ubuntu/lxml@4.5.0-1ubuntu0.3?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
4.5.0-1ubuntu0.3

Affected versions

4.*

4.4.1-1
4.4.1-1build1
4.4.2-1
4.5.0-1
4.5.0-1ubuntu0.1
4.5.0-1ubuntu0.2

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "python-lxml",
            "binary_version": "4.5.0-1ubuntu0.3"
        },
        {
            "binary_name": "python-lxml-dbg",
            "binary_version": "4.5.0-1ubuntu0.3"
        },
        {
            "binary_name": "python-lxml-doc",
            "binary_version": "4.5.0-1ubuntu0.3"
        },
        {
            "binary_name": "python3-lxml",
            "binary_version": "4.5.0-1ubuntu0.3"
        },
        {
            "binary_name": "python3-lxml-dbg",
            "binary_version": "4.5.0-1ubuntu0.3"
        }
    ]
}