Security Digest · Vulnerability record
CVE-2024-39205: pyload-ng vulnerable to RCE with js2py sandbox escape
An issue in pyload-ng v0.5.0b3.dev85 running under python3.11 or below allows attackers to execute arbitrary code via a crafted HTTP request.
CVSS 9.3 Critical EPSS 16.5% · p97
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.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 16.5%, percentile 97: FIRST’s model estimates a 16.5% chance of exploitation activity in the next 30 days, higher than 97% 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
pyload-ng(PyPI) <= 0.5.0b3.dev85, no fixed version listed. Check your lockfile, including transitive dependencies.
What it is
An issue in pyload-ng v0.5.0b3.dev85 running under python3.11 or below allows attackers to execute arbitrary code via a crafted HTTP request.
From the GitHub advisory
Summary Any pyload-ng running under python3.11 or below are vulnerable under RCE. Attacker can send a request containing any shell command and the victim server will execute it immediately.
Details js2py has a vulnerability of sandbox escape assigned as CVE-2024-28397, which is used by the /flash/addcrypted2 API endpoint of pyload-ng. Although this endpoint is designed to only accept localhost connection, we can bypass this restriction using HTTP Header, thus accessing this API and achieve RCE.
PoC
The PoC is provided as poc.py below, you can modify the shell command it execute:
Impact
Weakness type: CWE-94.
Product: pyload-ng (PyPI) · Assigned by: mitre · Published: 2024-10-28
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| PyPI | pyload-ng | <= 0.5.0b3.dev85 | none listed |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| n/a | n/a | see vendor advisory |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADP | 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
- 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 poc, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 16.54% probability of exploitation activity in the next 30 days; percentile 97.
Timeline
- — GitHub-reviewed advisory GHSA-r9pp-r4xf-597r published (critical)
- — CVE record published by mitre
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-r9pp-r4xf-597r github.com
- CVE.org record CVE-2024-39205 cve.org
- NVD entry CVE-2024-39205 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com
- github.com github.com
- github.com github.com
- github.com github.com