CVE-2021-43818

Home/CVE/lxml is a library for processing XML and HTML in the Python language. Prior to version 4.6.5, the HTML Cleaner in lxml.h

CVE

lxml is a library for processing XML and HTML in the Python language. Prior to version 4.6.5, the HTML Cleaner in lxml.h

lxml is a library for processing XML and HTML in the Python language. Prior to version 4.6.5, the HTML Cleaner in lxml.html lets certain crafted script content pass through, as well as script content in SVG files embedded using data URIs. Users that employ the HTML cleaner in a security relevant context should upgrade to lxml 4.6.5 to receive a patch.

There are no known workarounds available.

HIGH · CVSS 8.2 EPSS 0.05428

Schedule remediation

EPSS percentile: top 10% of all CVEs by exploitation likelihood
CVSS base score ≥ 7.0

Sigma rules0 YARA rules0

⬡

Weakness Classification

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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Affected Products & Versions

lxml< 4.6.5
fedoraproject fedoraall versions
debian linuxall versions
netapp solidfireall versions
netapp solidfire enterprise sdsall versions
netapp hci storage node firmwareall versions
oracle communications cloud native core binding support functionall versions
oracle communications cloud native core network exposure functionall versions
Show all 11 affected productsoracle communications cloud native core policyall versions
oracle http serverall versions
oracle zfs storage appliance kitall versions

▤

Affected Packages

Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.

PyPI lxml MODERATE fixed in 4.6.5

▣

Scoring & Timeline

8.2

HIGH · CVSS v3.1 · security-advisories@github.com

View on NVD

Attack Vector

Network Adjacent Local Physical

Attack Complexity

Low High

Privileges Required

None Low High

User Interaction

None Required

Scope

Unchanged Changed

Confidentiality

None Low High

Integrity

None Low High

Availability

None Low High

Published to NVD13 Dec 2021 · 06:15 PM

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N

SSVC triage · cisa-vulnrichment

Exploitation

none

Automatable

Technical impact

partial

SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.

⚑

Vendor Advisories

suse-csafopenSUSE-SU-2024:11713-1
suse-csafSUSE-SU-2022:1729-1
rhsaRHSA-2022:5498Important
suse-csafSUSE-SU-2022:0895-1
suse-csafopenSUSE-SU-2022:0803-1
Show all 14 vendor advisoriessuse-csafSUSE-SU-2022:0803-1
usnUSN-5225-1
rhsaRHSA-2022:1821Moderate
msrcCVE-2021-43818
rhsaRHSA-2022:1932Moderate
rhsaRHSA-2022:1764Moderate
rhsaRHSA-2022:1763Moderate
rhsaRHSA-2022:1664Moderate
oracle-cpuoracle-cpu-Oracle-Communications-Cloud-Native-Core-Binding-Support-Function-14121--CVE-2021-43818

🔗

References & Sources

Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.

https://github.com/lxml/lxml/commit/12fa9669007180a7bb87d990c375cf91ca5b664aPatchThird Party Advisory

https://github.com/lxml/lxml/commit/a3eacbc0dcf1de1c822ec29fb7d090a4b1712a9c#diff-59130575b4fb2932c957db2922977d7d89afb0b2085357db1a14615a2fcad776PatchThird Party Advisory

https://github.com/lxml/lxml/commit/f2330237440df7e8f39c3ad1b1aa8852be3b27c0PatchThird Party Advisory

https://github.com/lxml/lxml/security/advisories/GHSA-55x5-fj6c-h6m8Third Party Advisory

https://lists.debian.org/debian-lts-announce/2021/12/msg00037.htmlMailing ListThird Party Advisory

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TUIS2KE3HZ2AAQKXFLTJFZPP2IFHJTC7/

Show all 14 references

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V2XMOM5PFT6U5AAXY6EFNT5JZCKKHK2V/

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WZGNET2A4WGLSUXLBFYKNC5PXHQMI3I7/

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZQ4SPKJX3RRJK4UWA6FXCRHD2TVRQI44/

https://security.gentoo.org/glsa/202208-06Third Party Advisory

https://security.netapp.com/advisory/ntap-20220107-0005/Third Party Advisory

https://www.debian.org/security/2022/dsa-5043Third Party Advisory

https://www.oracle.com/security-alerts/cpuapr2022.htmlPatchThird Party Advisory

https://www.oracle.com/security-alerts/cpujul2022.htmlPatchThird Party Advisory

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