CVE-2023-49785: NextChat has full-read SSRF and XSS vulnerability in /api/cors endpoint

Should you act?

High exploit likelihood

EPSS ranks it in the top 5% of all CVEs for likely exploitation in the next 30 days. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 83.2%, percentile 99.7: FIRST’s model estimates a 83.2% chance of exploitation activity in the next 30 days, higher than 99.7% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes nextchat (npm) <= 2.11.2, no fixed version listed. Check your lockfile, including transitive dependencies.

What it is

NextChat, also known as ChatGPT-Next-Web, is a cross-platform chat user interface for use with ChatGPT. Versions 2.11.2 and prior are vulnerable to server-side request forgery and cross-site scripting. This vulnerability enables read access to internal HTTP endpoints but also write access using HTTP POST, PUT, and other methods. Attackers can also use this vulnerability to mask their source IP by forwarding malicious traffic intended for other Internet targets through these open proxies. As of time of publication, no patch is available, but other mitigation strategies are available. Users may avoid exposing the application to the public internet or, if exposing the application to the internet, ensure it is an isolated network with no access to any other internal resources.

From the GitHub advisory

NextChat, also known as ChatGPT-Next-Web, is a cross-platform chat user interface for use with ChatGPT. Versions 2.11.2 and prior are vulnerable to server-side request forgery and cross-site scripting. This vulnerability enables read access to internal HTTP endpoints but also write access using HTTP POST, PUT, and other methods. Attackers can also use this vulnerability to mask their source IP by forwarding malicious traffic intended for other Internet targets through these open proxies. As of time of publication, no patch is available, but other mitigation strategies are available. Users may avoid exposing the application to the public internet or, if exposing the application to the internet, ensure it is an isolated network with no access to any other internal resources.

Weakness type: CWE-918, CWE-79.

Product: nextchat (npm) · Assigned by: GitHub_M · Published: 2024-03-11

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 83.16% probability of exploitation activity in the next 30 days; percentile 99.7.

Timeline

• 2024-03-11 — CVE record published by GitHub_M
• 2024-08-05 — GitHub-reviewed advisory GHSA-qf3q-9f3h-cjp9 published (critical)
• 2024-08-19 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. github.com github.com

Vulnerability records

1. GitHub Advisory GHSA-qf3q-9f3h-cjp9 github.com
2. CVE.org record CVE-2023-49785 cve.org
3. NVD entry CVE-2023-49785 nvd.nist.gov

Other references from the CVE record and advisory

1. horizon3.ai horizon3.ai
2. github.com github.com
3. vicarius.io vicarius.io
4. github.com github.com

Critical npm advisories · Today’s Security Digest