CriticalCVE-2023-49103

    ownCloud graphapi Information Disclosure Vulnerability (CVE-2023-49103)

    Published In CISA KEV since Sources: BSI, SingCERT, NCSC NZ, pwn.watch, CVE.org

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    What is affected, what to do

    An issue was discovered in ownCloud owncloud/graphapi 0.2.x before 0.2.1 and 0.3.x before 0.3.1. The graphapi app relies on a third-party GetPhpInfo.php library that provides a URL.

    The vulnerability is being actively exploited; treat it as a priority. The available sources name no fixed version. Check the vendor guidance in the references below. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • ownCloud graphapi eq 0.2.0..0.2.0
    • ownCloud graphapi eq 0.3.0..0.3.0

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

    Metrics

    10.0

    Priority

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

    Source: Vendor (CNA), CVSS v3

    10.0

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: BSI, SingCERT, NCSC NZ, pwn.watch, CVE.org

    77.8 %

    EPSS score

    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.

    Source: FIRST EPSS, percentile 99.57

    Show all metrics
    Severity
    Critical
    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
    233.14 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
    actively exploitedSource: NCSC NZ, CSA/SingCERT How we classify
    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
    10.0 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
    10.0
    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“.

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    77.8 %
    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
    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
    99.57
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    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
    Actively exploited
    Published
    In CISA KEV since

    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
    CISA assessment (SSVC)
    Exploitation: active · automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 27 January 2025
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-200

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This CVE is on KEV because it is unauthenticated and network-reachable (AV:N/AC:L/PR:N/UI:N) and was mass-scanned within hours of disclosure — exploitation likelihood ranks among the highest in the entire KEV catalogue. The real risk is not the phpinfo page itself but the admin and service credentials it reveals, which attackers use to take full control of the ownCloud tenant and pivot (SMTP relay abuse, database access, lateral movement into Entra ID when SSO is configured). For NIS2-regulated organisations: treat every internet-exposed ownCloud instance as P1 and internal instances as P2 — and remember that patching alone is insufficient, because any credential that was reachable through phpinfo must be rotated regardless of when the patch was applied.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Upgrade the graphapi app to 0.2.1 or 0.3.1 immediately (ownCloud advisory, November 2023). After upgrade, manually verify and delete owncloud/apps/graphapi/vendor/microsoft/microsoft-graph/tests/GetPhpInfo.php — disabling the app alone does NOT remove the vulnerable file.
      • Front the instance with a reverse proxy or WAF rule that returns 403 for any request to /apps/graphapi/vendor/microsoft/microsoft-graph/tests/GetPhpInfo.php, generic */GetPhpInfo.php, and path-traversal variants containing /.%2E/.
      • Rotate every secret that could appear in phpinfo output: ownCloud admin password, SMTP credentials, object-storage keys (S3/Swift), database credentials, license key, OAuth client secrets, LDAP bind passwords. For containerised deployments (Docker/Kubernetes) treat all values stored as environment variables as compromised.
      • Hunt web-server access logs (nginx/Apache) retroactively back to at least 2023-11-01 for any hit on GetPhpInfo.php. Each hit opens a security incident and assumes successful exfiltration.
      • Prioritise container images built before February 2023 — these expose admin credentials directly through the process environment.
      • If patching cannot happen in the next maintenance window: disable the app via occ app:disable graphapi AND remove the GetPhpInfo.php file from disk. Doing only one of these is not enough.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: run ownCloud behind a reverse proxy with allowlist-based URL routing; default-deny for paths under /apps/*/vendor/, /tests/, /.git/, /config/.
      • WAF signature: block URI pattern (?i)/graphapi/.*GetPhpInfo\.php and inspect egress responses for X-Powered-By: PHP headers combined with response bodies > 50 KB on endpoints that are not supposed to return large payloads (ModSecurity/Coraza rule).
      • Container hardening: stop injecting secrets as environment variables. Mount them as files via Docker/K8s secrets, or load them from a secret vault (HashiCorp Vault, AWS Secrets Manager) at container start and unset them from the process environment afterwards.
      • IAM minimisation: restrict the admin account to MFA plus source-IP allowlist; create a dedicated service account for bulk operations and keep its credentials out of any phpinfo-reachable environment.
      • Configuration audit: review occ config:list system for hard-coded secrets in config.php; only migrate to environment-variable references once the container-hardening step above is in place.
      • External attack-surface scanning: periodic authenticated scan against /apps/graphapi/vendor/microsoft/microsoft-graph/tests/GetPhpInfo.php and known info-disclosure paths across all ownCloud instances in the estate.

    3. Runbook step 3

      Detection rules

      • Web access log (nginx/Apache): alert on any request matching GET .*graphapi.*GetPhpInfo\.php.* plus URL-encoded bypass variants (%2E, %2F, /.%2E/). SPL: index=web uri_path="*graphapi*GetPhpInfo.php*" OR uri_path="*/.%2E/*GetPhpInfo*" | stats count by src_ip, uri_path, status.
      • Zeek/Suricata HTTP log: rule on http.uri contains GetPhpInfo.php combined with response size > 20 KB — a typical phpinfo page is 50-150 KB.
      • Sigma shape: detection: selection: cs-uri-stem|contains: 'GetPhpInfo.php' sc-status: 200 condition: selection — severity high, since no legitimate traffic hits this path.
      • Post-exploitation follow-up: admin logins from previously unseen source IPs within 24 h of a GetPhpInfo request. KQL: OwnCloudAuditLog | where Action == "login" | join (WebAccessLog | where UriPath contains "GetPhpInfo.php") on $left.SrcIP == $right.SrcIP.
      • EDR on the ownCloud host: unexpected php-fpm child processes spawning curl, wget, or shells — indicates follow-on activity using the leaked admin credentials.

    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
    Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
    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
    Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
    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

    An issue was discovered in ownCloud owncloud/graphapi 0.2.x before 0.2.1 and 0.3.x before 0.3.1. The graphapi app relies on a third-party GetPhpInfo.php library that provides a URL. When this URL is accessed, it reveals the configuration details of the PHP environment (phpinfo). This information includes all the environment variables of the webserver. In containerized deployments, these environment variables may include sensitive data such as the ownCloud admin password, mail server credentials, and license key. Simply disabling the graphapi app does not eliminate the vulnerability. Additionally, phpinfo exposes various other potentially sensitive configuration details that could be exploited by an attacker to gather information about the system. Therefore, even if ownCloud is not running in a containerized environment, this vulnerability should still be a cause for concern. Note that Docker containers from before February 2023 are not vulnerable to the credential disclosure.

    Source: BSI CSAF, BSI WID Portal, CSA/SingCERT, NCSC NZ (CC BY 4.0), pwn.watch, NVD (NIST), cvelistv5, CISA KEV Catalog, CVE.org (MITRE)

    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
    owncloudgraph_api
    • 0.2.0
    • 0.3.0
    • —
    • —
    ownCloudownCloud
    • <graphapi 0.3.1
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-200Exposure of Sensitive Information to an Unauthorized Actor

      Class

      The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

      Entry at MITRE CWE-200

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CISA KEV CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited
    CSA/SingCERTCritical Vulnerabilities in ownCloud File Sharing Application (opens in a new tab)CSA/SingCERTactively exploited
    NCSC NZThree critical vulnerabilities affecting ownCloud software (opens in a new tab)NCSC NZactively exploited

    References & sources

    • owncloud.orgsecurityProduct
    • owncloud.comVendor advisory: ownCloud graphapiVendor advisory, pwn-watch
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2023-49103government-resource, US government resource
    • pwn.watchpwn.watch: ownCloud graphapi: Information Disclosure (CVE-2023-49103)pwn-watch
    • NVD (NIST)NVD: CVE-2023-49103pwn-watch
    • cisa.govCISA Known Exploited Vulnerabilities Catalogpwn-watch
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