CVE-2026-56425 : 詳細

CVE-2026-56425

8.8
/
高
2026-06-22
14h17 +00:00
A07-Identif. and Authent. Fail
Network
2026-06-26
20h33 +00:00
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CVE の説明

The Azure Active Directory (AAD) authentication implementation contained multiple weaknesses in its OAuth 2.0 authorization flow that could allow attackers to bypass important security guarantees provided by the protocol. The application used the PHP session identifier (session_id()) as the OAuth state parameter. Because session identifiers are long-lived authentication credentials, exposing them in OAuth redirect URLs could leak valid session tokens through browser history, HTTP Referer headers, reverse proxies, access logs, or third-party infrastructure involved in the authentication flow. If obtained by an attacker, the leaked session identifier could potentially be used for session hijacking. Additionally, the implementation did not regenerate the session identifier after successful authentication, leaving authenticated sessions susceptible to session fixation attacks where an attacker forces a victim to use a known session identifier before login and later reuses that identifier after authentication. The OAuth state value was also not implemented as a dedicated, single-use nonce. This weakened CSRF protections and increased the risk of replay attacks against the OAuth callback process. The authentication flow further failed to enforce HTTPS for the configured OAuth redirect URI. If a non-HTTPS redirect URI was used, OAuth authorization codes and access tokens could traverse the network in plaintext, exposing sensitive credentials to network attackers. Finally, OAuth error responses containing attacker-controlled GET parameters were logged verbatim. An attacker could inject control characters or crafted log content, leading to log forging, log injection, or corruption of audit records. The fix introduces: * A dedicated cryptographically random OAuth state value. * Single-use state validation and invalidation. * Constant-time state comparison using hash_equals(). * Session identifier rotation after successful authentication. * Enforcement of HTTPS-only redirect URIs. * Sanitized and length-limited logging of OAuth error parameters. AAD Authentication Plugin (OAuth 2.0 / Azure Active Directory integration)

CVE の情報

関連する弱点

CWE-ID 弱点名 出典
CWE-384 Session Fixation
Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.

メトリクス

メトリクス スコア 深刻度 CVSS ベクター 出典
V3.1 8.8 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Network

The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).

Attack Complexity

This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

None

The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.

User Interaction

This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component.

Required

Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited. For example, a successful exploit may only be possible during the installation of an application by a system administrator.

Base: Scope Metrics

The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope.

Scope

Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs.

Unchanged

An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.

Base: Impact Metrics

The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

High

There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability.

Environmental Metrics

These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.

nvd@nist.gov

関連製品

構成 0

Misp-project>>Misp >> Version ~まで(含まない) 2.5.42

参考資料