curl supports "chained" HTTP compression algorithms, meaning that a server response can be compressed multiple times and potentially with different algorithms. The number of acceptable "links" in this "decompression chain" was unbounded, allowing a malicious server to insert a virtually unlimited number of compression steps.
The use of such a decompression chain could result in a "malloc bomb", making curl end up spending enormous amounts of allocated heap memory, or trying to and returning out of memory errors.
{ "CWE": { "desc": "Allocation of Resources Without Limits or Throttling", "id": "CWE-770" }, "package": "curl", "URL": "https://curl.se/docs/CVE-2022-32206.json", "www": "https://curl.se/docs/CVE-2022-32206.html", "last_affected": "7.83.1", "award": { "amount": "2400", "currency": "USD" }, "severity": "Medium", "affects": "both", "issue": "https://hackerone.com/reports/1570651" }