CVE-2024-8901VulnerabilityPublished 21 Oct 2024Updated 14 Oct 2025

CVE-2024-8901: AWS ALB Route Directive Adapter For Istio · Authentication Bypass by Spoofing

Affects AWS ALB Route Directive Adapter For IstioSource CVE Database V5

Not known to be exploited · CVSS 6.9 Medium · end of life, no fix coming : replace or isolate AWS ALB Route Directive Adapter For Istio; no fix will be released.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 4.0 base score

6.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: None coming – the product is end of life

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: Present
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: High
Subsequent system integrity: Low
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system 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: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: Present: The successful attack depends on the presence of specific deployment and execution conditions of the vulnerable system that enable the attack. These include: a race condition must be won to successfully exploit the vulnerability (the successfulness of the attack is conditioned on execution conditions that are not under full control of the attacker, or the attack may need to be launched multiple times against a single target before being successful); the attacker must inject themselves into the logical network path between the target and the resource requested by the victim (e.g. vulnerabilities requiring an on-path attacker).
Privileges Required: 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: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: High: There is a total loss of confidentiality, resulting in all resources within the Subsequent System 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.
Subsequent system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Subsequent System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Oct 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

No fix will be released: AWS ALB Route Directive Adapter For Istio is end of life. Replace it, or isolate it from untrusted networks until you can.

Affected software

Product	Affected	Fixed in
Amazon AWS ALB Route Directive Adapter For Istio	Affected =1.0 =1.1	Fixed in–

AI-suggested

1. Immediately audit all AWS ALB deployments to verify that ELB targets (EC2 instances, Fargate tasks, etc.) do not have public IP addresses or direct internet exposure. Use private subnets and internal load balancers where possible. 2. For any forks or derivative versions of the AWS ALB Route Directive Adapter for Istio, implement strict validation of the JWT token's signer attribute, ensuring it matches the ARN of the ALB configured for the service. 3. Consider migrating away from the deprecated adapter to supported and actively maintained authentication solutions that enforce robust JWT validation, including issuer and signature verification. 4. Employ network segmentation and strict security group rules to limit inbound traffic to ALB targets only from trusted sources. 5. Monitor authentication logs for anomalous JWT tokens or unexpected signers to detect potential spoofing attempts. 6. Integrate runtime security tools that can detect and alert on suspicious authentication bypass activities in Kubernetes and Istio environments. 7. Educate DevOps and security teams about the risks of using deprecated open-source components and enforce policies for regular dependency and security reviews. 8. Engage with AWS support or security teams for guidance on best practices and potential compensating controls in the absence of patches.

Description

The AWS ALB Route Directive Adapter For Istio repo https://github.com/awslabs/aws-alb-route-directive-adapter-for-istio/tree/master provides an OIDC authentication mechanism that was integrated into the open source Kubeflow project. The adapter uses JWT for authentication, but lacks proper signer and issuer validation. In deployments of ALB that ignore security best practices, where ALB targets are directly exposed to internet traffic, an actor can provide a JWT signed by an untrusted entity in order to spoof OIDC-federated sessions and successfully bypass authentication. The repository/package has been deprecated, is end of life, and is no longer supported. As a security best practice, ensure that your ELB targets (e.g. EC2 Instances, Fargate Tasks etc.) do not have public IP addresses. Ensure any forked or derivative code validate that the signer attribute in the JWT match the ARN of the Application Load Balancer that the service is configured to use.

Impact

For European organizations, this vulnerability poses a risk of unauthorized access to cloud-native applications and services that rely on the AWS ALB Route Directive Adapter for Istio for authentication. Successful exploitation can lead to authentication bypass, allowing attackers to impersonate legitimate users or services without valid credentials. This can result in data exposure, unauthorized actions within applications, and potential lateral movement within cloud environments. The impact is heightened in environments where ALB targets are publicly accessible, increasing the attack surface. Given the adapter's integration with Kubeflow and Istio, critical workloads related to machine learning pipelines or microservices could be compromised. This could affect confidentiality and integrity of sensitive data and disrupt service availability if attackers leverage access to escalate privileges or deploy malicious payloads. The lack of official patches and the adapter's deprecated status complicate remediation efforts, potentially prolonging exposure. European organizations with cloud deployments on AWS, particularly those using Kubernetes, Istio, and Kubeflow, must be vigilant. The risk is amplified in sectors with stringent data protection requirements such as finance, healthcare, and government, where unauthorized access could lead to regulatory penalties and reputational damage.

Summary

CVE-2024-8901 is a medium-severity authentication bypass vulnerability identified in the AWS ALB Route Directive Adapter for Istio, a component that integrates OIDC authentication using JWT tokens within cloud-native environments, including Kubeflow deployments. The core issue lies in the adapter's failure to properly validate the JWT token's signer and issuer fields, which are critical to confirming the token's authenticity and origin. Without this validation, an attacker can craft a JWT signed by an untrusted or malicious entity and present it to the ALB, effectively spoofing a legitimate OIDC-federated session and bypassing authentication controls. This vulnerability is particularly exploitable in deployments where the ALB targets, such as EC2 instances or Fargate tasks, are directly exposed to the internet, a configuration that contradicts AWS security best practices. The adapter versions 1.0 and 1.1 are affected, but the project is deprecated and no longer maintained, meaning no official patches are available. The CVSS 4.0 vector indicates a network attack vector with low attack complexity and no user interaction, but partial impact on integrity and limited scope. Although no known exploits are currently in the wild, the risk remains significant for misconfigured environments. Organizations using this adapter or forks thereof must audit their deployments to ensure ELB targets are not publicly accessible and must implement strict validation of JWT signer attributes, ideally matching the ARN of the ALB in use. This vulnerability highlights the risks of relying on deprecated open-source components without ongoing security maintenance, especially in complex cloud-native authentication scenarios.

CWE-290Authentication Bypass by Spoofing (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
OWASP Cheat Sheets
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V3.5.1 (opens in a new tab)
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
Attack patterns
Creating a Rogue Certification Authority Certificate (opens in a new tab)
Web Services API Signature Forgery Leveraging Hash Function Extension Weakness (opens in a new tab)
Signature Spoof (opens in a new tab)
Signature Spoofing by Misrepresentation (opens in a new tab)
Session Credential Falsification through Prediction (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 14 Oct 2025, 19:20 UTC

WeaknessesCWE-290

Technical details

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