LiveActive security incident?Get immediate response
CVE Record

CVE-2017-8872: The htmlParseTryOrFinish function in HTMLparser.c in libxml2 2.9.4 allows attackers to cause a denial of se...

The htmlParseTryOrFinish function in HTMLparser.c in libxml2 2.9.4 allows attackers to cause a denial of service (buffer over-read) or information disclosure.

CriticalCVSS 9.1Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

This flaw is in libxml2 2.9.4, a widely used parsing library. Malformed HTML can trigger a buffer over-read, causing service crashes or possible information disclosure. The supplied sources do not show active exploitation, but the CVSS score is critical because exploitation is network-reachable, low complexity, and requires no privileges or user interaction.

Executive priority

Treat this as a high-priority remediation item for externally exposed parsing paths. It is old, but library vulnerabilities persist through embedded dependencies and long-lived systems. Patch verification matters more than CVE age.

Technical view

CVE-2017-8872 affects htmlParseTryOrFinish in HTMLparser.c in libxml2 2.9.4. It is categorized as CWE-125, buffer over-read. The CVSS 3.1 vector is AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H, indicating potential high confidentiality and availability impact without integrity impact.

Likely exposure

Exposure is most likely where applications or services use vulnerable libxml2 builds to parse untrusted HTML. The source bundle names libxml2 2.9.4 specifically, but does not provide a complete affected-version range or product inventory.

Exploitation context

The provided sources and KEV flag do not support a claim of known active exploitation. The risk comes from unauthenticated remote parsing of malicious HTML, potentially leading to denial of service or information disclosure.

Researcher notes

Evidence is limited to the CVE record, GNOME bug reference, and Debian LTS advisory. Do not assume affected ranges beyond the cited libxml2 2.9.4 without vendor-specific confirmation. Debian’s advisory indicates distribution-level remediation existed for supported packages.

Mitigation direction

  • Inventory systems and applications using libxml2 2.9.4.
  • Apply vendor security updates for libxml2 where available.
  • Prioritize internet-facing services that parse untrusted HTML.
  • Check distribution advisories for backported fixes.
  • Reduce acceptance of untrusted HTML where operationally possible.

Validation and detection

  • Confirm installed libxml2 versions across hosts and containers.
  • Check package changelogs for CVE-2017-8872 coverage.
  • Identify services that invoke libxml2 HTML parsing on external input.
  • Review crash telemetry for parser-related faults.
  • Verify Debian systems received relevant libxml2 security updates.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-125: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2017-8872 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.1 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
9.1CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H3.95.2Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

9.1Critical
CVSS 3.1 vector shape for CVE-2017-8872Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

CWE-125

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-125 · source CWE mapping

Out-of-bounds Read

Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs