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CVE-2023-38545: SOCKS5 heap buffer overflow

Update: https://curl.se/docs/CVE-2023-38545.html

This flaw makes curl overflow a heap based buffer in the SOCKS5 proxy handshake.

When curl is asked to pass along the hostname to the SOCKS5 proxy to allow that to resolve the address instead of it getting done by curl itself, the maximum length that hostname can be is 255 bytes.

If the hostname is detected to be longer than 255 bytes, curl switches to local name resolving and instead passes on the resolved address only to the proxy. Due to a bug, the local variable that means "let the host resolve the name" could get the wrong value during a slow SOCKS5 handshake, and contrary to the intention, copy the too long hostname to the target buffer instead of copying just the resolved address there.

https://github.com/curl/curl/discussions/12026

Filing this under admin instead of fdroiddata as it probably also affects our own infrastructure, and few apps.

Will run a scan for libcurl on repo/ soon. [Edit: done]

Infra

  • unattended-upgrades should handle most updates
    • fdroidstatus.org & staging.fdroidstatus.org
  • might need to restart some things using libcurl
  • @eighthave will run makebuildserver
  • container/CI images (?)

Apps

Other

  • packages like libvirt, cargo, etc. use libcurl
  • apt in Debian doesn't seem to use libcurl
Edited by Licaon_Kter
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