zrok: Unauthenticated DoS via unbounded memory allocation in striped session cookie parsing
Exact source revision recorded 24 Oct 2026 13:19:41 UTC. It does not establish the source's current position. Latest evidence.
osv · GHSA-cpf9-ph2j-ccr9
Published**Summary** endpoints.GetSessionCookie parses an attacker-supplied cookie chunk count and calls make([]string, count) with no upper bound before any token validation occurs. The function is reached on every request to an OAuth-protected proxy share, allowing an unauthenticated remote attacker to trigger gigabyte-scale heap allocations per request, leading to process-level OOM termination or repeated goroutine panics. Both publicProxy and dynamicProxy are affected. - Attack Vector: Network — exploitable via a single HTTP request with a crafted Cookie header. - Attack Complexity: Low — no preconditions or chaining required; the attacker only needs to know the cookie name (publicly derivable from any OAuth redirect). - Privileges Required: None — reached before JWT validation or any authentication check. - User Interaction: None. - Scope: Unchanged — impact is confined to the affected proxy process. - Confidentiality Impact: None. - Integrity Impact: None. Availability Impact: High — sustained or concurrent requests cause OOM process termination, taking down the proxy for all users of all shares it serves. **Affected Components** - endpoints/oauthCookies.go — GetSessionCookie (line 81) - endpoints/publicProxy/authOAuth.go — handleOAuth (line 50) — call site, pre-auth - endpoints/dynamicProxy/cookies.go — getSessionCookie (line 29) — call site
- Source published
- 16 Apr 2026 21:09:08 UTC
- Source modified
- 25 Jun 2026 19:56:15 UTC
- Observed here
- 24 Oct 2026 13:19:41 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Publisher rating · HIGH