CVE-2026-28808 (GCVE-0-2026-28808)

Vulnerability from cvelistv5 – Published: 2026-04-07 12:28 – Updated: 2026-04-07 14:38
VLAI?
Title
ScriptAlias CGI targets bypass directory auth in inets httpd (mod_auth vs mod_cgi path mismatch)
Summary
Incorrect Authorization vulnerability in Erlang OTP (inets modules) allows unauthenticated access to CGI scripts protected by directory rules when served via script_alias. When script_alias maps a URL prefix to a directory outside DocumentRoot, mod_auth evaluates directory-based access controls against the DocumentRoot-relative path while mod_cgi executes the script at the ScriptAlias-resolved path. This path mismatch allows unauthenticated access to CGI scripts that directory rules were meant to protect. This vulnerability is associated with program files lib/inets/src/http_server/mod_alias.erl, lib/inets/src/http_server/mod_auth.erl, and lib/inets/src/http_server/mod_cgi.erl. This issue affects OTP from OTP 17.0 until OTP 28.4.2, 27.3.4.10 and 26.2.5.19 corresponding to inets from 5.10 until 9.6.2, 9.3.2.4 and 9.1.0.6.
Severity ?
8.3 (High)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
CWE
  • CWE-863 - Incorrect Authorization
Assigner
EEF
References
Impacted products
Vendor Product Version
Erlang OTP Affected: 5.10 , < * (otp)
    cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:*
 Create a notification for this product.
    Erlang OTP Affected: 17.0 , < * (otp)
Affected: 07b8f441ca711f9812fad9e9115bab3c3aa92f79 , < * (git)
    cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:*
 Create a notification for this product.
Credits
Igor Morgenstern / Aisle Research Konrad Pietrzak
Show details on NVD website
To clipboard 

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Accessing Functionality Not Properly Constrained by ACLs\"}]}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 8.3, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N\", \"exploitMaturity\": \"NOT_DEFINED\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"PRESENT\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"LOW\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"NONE\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"HIGH\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"cpes\": [\"cpe:2.3:a:erlang:erlang\\\\/otp:*:*:*:*:*:*:*:*\"], \"repo\": \"https://github.com/erlang/otp\", \"vendor\": \"Erlang\", \"modules\": [\"inets\"], \"product\": \"OTP\", \"versions\": [{\"status\": \"affected\", \"changes\": [{\"at\": \"9.6.2\", \"status\": \"unaffected\"}, {\"at\": \"9.3.2.4\", \"status\": \"unaffected\"}, {\"at\": \"9.1.0.6\", \"status\": \"unaffected\"}], \"version\": \"5.10\", \"lessThan\": \"*\", \"versionType\": \"otp\"}], \"packageURL\": \"pkg:otp/inets?repository_url=https:%2F%2Fgithub.com%2Ferlang%2Fotp\u0026vcs_url=git%20https:%2F%2Fgithub.com%2Ferlang%2Fotp.git\", \"packageName\": \"inets\", \"programFiles\": [\"src/http_server/mod_alias.erl\", \"src/http_server/mod_auth.erl\", \"src/http_server/mod_cgi.erl\"], \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:2.3:a:erlang:erlang\\\\/otp:*:*:*:*:*:*:*:*\"], \"repo\": \"https://github.com/erlang/otp\", \"vendor\": \"Erlang\", \"modules\": [\"inets\"], \"product\": \"OTP\", \"versions\": [{\"status\": \"affected\", \"changes\": [{\"at\": \"28.4.2\", \"status\": \"unaffected\"}, {\"at\": \"27.3.4.10\", \"status\": \"unaffected\"}, {\"at\": \"26.2.5.19\", \"status\": \"unaffected\"}], \"version\": \"17.0\", \"lessThan\": \"*\", \"versionType\": \"otp\"}, {\"status\": \"affected\", \"changes\": [{\"at\": \"8fc71ac6af4fbcc54103bec2983ef22e82942688\", \"status\": \"unaffected\"}, {\"at\": \"9dfa0c51eac97866078e808dec2183cb7871ff7c\", \"status\": \"unaffected\"}], \"version\": \"07b8f441ca711f9812fad9e9115bab3c3aa92f79\", \"lessThan\": \"*\", \"versionType\": \"git\"}], \"packageURL\": \"pkg:github/erlang/otp\", \"packageName\": \"erlang/otp\", \"programFiles\": [\"lib/inets/src/http_server/mod_alias.erl\", \"lib/inets/src/http_server/mod_auth.erl\", \"lib/inets/src/http_server/mod_cgi.erl\"], \"collectionURL\": \"https://github.com\", \"defaultStatus\": \"affected\"}], \"references\": [{\"url\": \"https://github.com/erlang/otp/security/advisories/GHSA-3vhp-h532-mc3f\", \"tags\": [\"vendor-advisory\", \"related\"]}, {\"url\": \"https://cna.erlef.org/cves/CVE-2026-28808.html\", \"tags\": [\"related\"]}, {\"url\": \"https://osv.dev/vulnerability/EEF-CVE-2026-28808\", \"tags\": [\"related\"]}, {\"url\": \"https://www.erlang.org/doc/system/versions.html#order-of-versions\", \"tags\": [\"x_version-scheme\"]}, {\"url\": \"https://github.com/erlang/otp/commit/8fc71ac6af4fbcc54103bec2983ef22e82942688\", \"tags\": [\"patch\"]}, {\"url\": \"https://github.com/erlang/otp/commit/9dfa0c51eac97866078e808dec2183cb7871ff7c\", \"tags\": [\"patch\"]}], \"workarounds\": [{\"lang\": \"en\", \"value\": \"* Move CGI scripts inside DocumentRoot and use alias instead of script_alias to ensure mod_auth resolves the correct path.\\n* Apply URL-based access controls at a reverse proxy layer to block unauthenticated access to the script_alias URL prefix.\\n* Remove mod_cgi from the httpd modules chain if CGI functionality is not required.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cul\u003e\u003cli\u003eMove CGI scripts inside \u003ctt\u003eDocumentRoot\u003c/tt\u003e and use \u003ctt\u003ealias\u003c/tt\u003e instead of \u003ctt\u003escript_alias\u003c/tt\u003e to ensure \u003ctt\u003emod_auth\u003c/tt\u003e resolves the correct path.\u003c/li\u003e\u003cli\u003eApply URL-based access controls at a reverse proxy layer to block unauthenticated access to the \u003ctt\u003escript_alias\u003c/tt\u003e URL prefix.\u003c/li\u003e\u003cli\u003eRemove \u003ctt\u003emod_cgi\u003c/tt\u003e from the httpd modules chain if CGI functionality is not required.\u003c/li\u003e\u003c/ul\u003e\", \"base64\": false}]}], \"x_generator\": {\"engine\": \"Vulnogram 0.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"Incorrect Authorization vulnerability in Erlang OTP (inets modules) allows unauthenticated access to CGI scripts protected by directory rules when served via script_alias.\\n\\nWhen script_alias maps a URL prefix to a directory outside DocumentRoot, mod_auth evaluates directory-based access controls against the DocumentRoot-relative path while mod_cgi executes the script at the ScriptAlias-resolved path. This path mismatch allows unauthenticated access to CGI scripts that directory rules were meant to protect.\\n\\nThis vulnerability is associated with program files lib/inets/src/http_server/mod_alias.erl, lib/inets/src/http_server/mod_auth.erl, and lib/inets/src/http_server/mod_cgi.erl.\\n\\nThis issue affects OTP from OTP 17.0 until OTP 28.4.2, 27.3.4.10 and 26.2.5.19 corresponding to inets from 5.10 until 9.6.2, 9.3.2.4 and 9.1.0.6.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"Incorrect Authorization vulnerability in Erlang OTP (inets modules) allows unauthenticated access to CGI scripts protected by \u003ctt\u003edirectory\u003c/tt\u003e rules when served via \u003ctt\u003escript_alias\u003c/tt\u003e.\u003cp\u003eWhen \u003ctt\u003escript_alias\u003c/tt\u003e maps a URL prefix to a directory outside \u003ctt\u003eDocumentRoot\u003c/tt\u003e, \u003ctt\u003emod_auth\u003c/tt\u003e evaluates \u003ctt\u003edirectory\u003c/tt\u003e-based access controls against the \u003ctt\u003eDocumentRoot\u003c/tt\u003e-relative path while \u003ctt\u003emod_cgi\u003c/tt\u003e executes the script at the \u003ctt\u003eScriptAlias\u003c/tt\u003e-resolved path. This path mismatch allows unauthenticated access to CGI scripts that \u003ctt\u003edirectory\u003c/tt\u003e rules were meant to protect.\u003c/p\u003e\u003cp\u003eThis vulnerability is associated with program files \u003ctt\u003elib/inets/src/http_server/mod_alias.erl\u003c/tt\u003e, \u003ctt\u003elib/inets/src/http_server/mod_auth.erl\u003c/tt\u003e, and \u003ctt\u003elib/inets/src/http_server/mod_cgi.erl\u003c/tt\u003e.\u003c/p\u003e\u003cp\u003eThis issue affects OTP from OTP 17.0 until OTP 28.4.2, 27.3.4.10 and 26.2.5.19 corresponding to inets from 5.10 until 9.6.2, 9.3.2.4 and 9.1.0.6.\u003c/p\u003e\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-863\", \"description\": \"CWE-863 Incorrect Authorization\"}]}], \"configurations\": [{\"lang\": \"en\", \"value\": \"The inets httpd server must use script_alias to map a URL prefix to a CGI directory, combined with directory-based access controls (e.g., mod_auth) protecting the script_alias target path. The vulnerability applies whenever the script_alias target path differs from DocumentRoot + URL prefix.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"The inets httpd server must use \u003ctt\u003escript_alias\u003c/tt\u003e to map a URL prefix to a CGI directory, combined with \u003ctt\u003edirectory\u003c/tt\u003e-based access controls (e.g., \u003ctt\u003emod_auth\u003c/tt\u003e) protecting the \u003ctt\u003escript_alias\u003c/tt\u003e target path. The vulnerability applies whenever the \u003ctt\u003escript_alias\u003c/tt\u003e target path differs from \u003ctt\u003eDocumentRoot\u003c/tt\u003e + URL prefix.\", \"base64\": false}]}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:a:erlang:erlang\\\\/otp:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"26.2.5.19\", \"versionStartIncluding\": \"17.0\"}, {\"criteria\": \"cpe:2.3:a:erlang:erlang\\\\/otp:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"27.3.4.10\", \"versionStartIncluding\": \"27.0\"}, {\"criteria\": \"cpe:2.3:a:erlang:erlang\\\\/otp:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"28.4.2\", \"versionStartIncluding\": \"28.0\"}], \"operator\": \"OR\"}], \"operator\": \"AND\"}], \"providerMetadata\": {\"orgId\": \"6b3ad84c-e1a6-4bf7-a703-f496b71e49db\", \"shortName\": \"EEF\", \"dateUpdated\": \"2026-04-07T14:38:09.190Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-28808\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-04-07T14:38:09.190Z\", \"dateReserved\": \"2026-03-03T14:40:00.590Z\", \"assignerOrgId\": \"6b3ad84c-e1a6-4bf7-a703-f496b71e49db\", \"datePublished\": \"2026-04-07T12:28:16.056Z\", \"assignerShortName\": \"EEF\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


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Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.