HighCVE-2019-9854

    Unsafe URL assembly flaw in allowed script location check (CVE-2019-9854)

    Published Sources: CVE.org

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    What is affected, what to do

    LibreOffice has a feature where documents can specify that pre-installed macros can be executed on various script events such as mouse-over, document-open etc. Access is intended to be restricted to scripts under the share/Scripts/python, user/Scripts/python sub-directories of the LibreOffice install. Protection was added, to address CVE-2019-9852, to avoid a directory traversal attack where scripts in arbitrary locations on the file system could be executed by employing a URL encoding attack to defeat the path verification step.

    Update Document Foundation LibreOffice to version 6.2.7, Document Foundation LibreOffice to version 6.3.1.

    Affected
    • Document Foundation LibreOffice lt 6.2..6.2.7
    • Document Foundation LibreOffice lt 6.3..6.3.1
    Fixed in
    • Document Foundation LibreOffice 6.2.7
    • Document Foundation LibreOffice 6.3.1

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    7.8

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    7.8

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: CVE.org

    1.8 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 78.0

    Show all metrics
    Severity
    High
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    87.70 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    7.8 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    7.8
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    1.8 %
    Moderate — model estimates 1-10% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    78.0
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    LibreOffice has a feature where documents can specify that pre-installed macros can be executed on various script events such as mouse-over, document-open etc. Access is intended to be restricted to scripts under the share/Scripts/python, user/Scripts/python sub-directories of the LibreOffice install. Protection was added, to address CVE-2019-9852, to avoid a directory traversal attack where scripts in arbitrary locations on the file system could be executed by employing a URL encoding attack to defeat the path verification step. However this protection could be bypassed by taking advantage of a flaw in how LibreOffice assembled the final script URL location directly from components of the passed in path as opposed to solely from the sanitized output of the path verification step. This issue affects: Document Foundation LibreOffice 6.2 versions prior to 6.2.7; 6.3 versions prior to 6.3.1.

    Source: NVD (NIST), cvelistv5

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    Document FoundationLibreOffice
    • 6.2 – < 6.2.7
    • 6.3 – < 6.3.1
    • 6.2.7
    • 6.3.1
    libreofficelibreoffice
    • 6.2.0 – < 6.2.7
    • 6.3.0 – < 6.3.1
    • 6.2.7
    • 6.3.1

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebiandebian_linux10.0
    Linuxdebiandebian_linux8.0
    Linuxdebiandebian_linux9.0
    Linuxredhatenterprise_linux7.0
    Linuxredhatenterprise_linux8.0
    Linuxopensuseleap15.0
    Linuxopensuseleap15.1
    Linuxcanonicalubuntu_linux16.04
    Linuxcanonicalubuntu_linux18.04
    Linuxcanonicalubuntu_linux19.04
    Otherfedoraprojectfedora29

    References & sources

    • libreoffice.orgabout-us/security/advisories/CVE-2019-9854x_refsource_CONFIRM, Vendor advisory
    • debian.orgDSA-4519Vendor advisory, x_refsource_DEBIAN, Third-party advisory
    • seclists.org20190910 [SECURITY] [DSA 4519-1] libreoffice security updateMailing list, x_refsource_BUGTRAQ, Mailing list, Third-party advisory
    • lists.fedoraproject.orgFEDORA-2019-9627e1402eVendor advisory, x_refsource_FEDORA
    • usn.ubuntu.comUSN-4138-1Vendor advisory, x_refsource_UBUNTU, Third-party advisory
    • lists.opensuse.orgopenSUSE-SU-2019:2183Vendor advisory, x_refsource_SUSE, Third-party advisory
    • lists.debian.org[debian-lts-announce] 20191006 [SECURITY] [DLA 1947-1] libreoffice security updateMailing list, x_refsource_MLIST, Third-party advisory
    • lists.opensuse.orgopenSUSE-SU-2019:2361Vendor advisory, x_refsource_SUSE, Third-party advisory
    • bugzilla.redhat.comshow_bug.cgi?id=1769907Third-party advisory
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