CyberRota Analysis
AI-GeneratedPomerium versions prior to 0.32.8 are vulnerable to a denial-of-service attack due to improper handling of zstd decompression in the decodeQueryStringV2 function, allowing unauthenticated attackers to send crafted payloads that can exhaust memory resources. This vulnerability can lead to application crashes or degraded performance in hosted or stateless authentication deployments, making it critical for organizations using Pomerium in these configurations to prioritize upgrading to the patched version. Stateful deployments are not affected, as they include additional verification steps that mitigate this risk.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
Note: these links are listed for security research and verification purposes only.
Original NVD Description
Pomerium is an identity and context-aware access proxy. Prior to 0.32.8, decodeQueryStringV2 in pkg/hpke/url.go performs zstd decompression of attacker-controlled data without an output-memory limit when DecryptURLValues processes HPKE V2 values for Stateless.Callback in internal/authenticateflow/stateless.go. In hosted or stateless authentication deployments, an unauthenticated attacker can obtain the receiver key from /.well-known/pomerium/hpke-public-key, provide a matching attacker-controlled sender key, and send a compressed payload to /.pomerium/callback that expands before validateSenderPublicKey rejects the sender. This can allocate hundreds of megabytes per request, exhaust proxy memory, crash or degrade the process, and block access to applications protected by the deployment. Stateful deployments are not affected because the stateful callback verifies its HMAC signature before decryption and decompression. This issue is fixed in version 0.32.8.