Rustls vulnerable to an infinite loop in rustls::conn::ConnectionCommon::complete_io() with proper client input
Priority MEDIUM 41CWE-835Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-835.
Summary
Rustls is a modern TLS library written in Rust. `rustls::ConnectionCommon::complete_io` could fall into an infinite loop based on network input. When using a blocking rustls server, if a client send a `close_notify` message immediately after `client_hello`, the server's `complete_io` will get in an infinite loop. This vulnerability is fixed in 0.23.5, 0.22.4, and 0.21.11.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00949 61st percentileScored 2026-11-07
Fix Fixed rustls (rustls): 0.23.5, 0.22.4, 0.21.11rustls (crates.io): 0.23.5, 0.22.4, 0.21.11
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| rustls | rustls | 0.23.0 to before 0.23.5; 0.22.0 to before 0.22.4; 0.21.0 to before 0.21.11; = 0.20.0 | 0.23.5, 0.22.4, 0.21.11 | Patch available | CNA |
| — | rustls (crates.io) | 0.23.0 to before 0.23.5 | 0.23.5 | Patch available | GHSA-6g7w-8wpp-frhj |
| — | rustls (crates.io) | 0.22.0 to before 0.22.4 | 0.22.4 | Patch available | GHSA-6g7w-8wpp-frhj |
| — | rustls (crates.io) | 0.21.0 to before 0.21.11 | 0.21.11 | Patch available | GHSA-6g7w-8wpp-frhj |
| — | rustls (crates.io) | — | — | No fix listed | GHSA-6g7w-8wpp-frhj |
- rustls Vendorrustls Affected 0.23.0 to before 0.23.5; 0.22.0 to before 0.22.4; 0.21.0 to before 0.21.11; = 0.20.0 Fixed in 0.23.5, 0.22.4, 0.21.11 Patch available CNA
- rustls (crates.io) Vendor— Affected 0.23.0 to before 0.23.5 Fixed in 0.23.5 Patch available GHSA-6g7w-8wpp-frhj
- rustls (crates.io) Vendor— Affected 0.22.0 to before 0.22.4 Fixed in 0.22.4 Patch available GHSA-6g7w-8wpp-frhj
- rustls (crates.io) Vendor— Affected 0.21.0 to before 0.21.11 Fixed in 0.21.11 Patch available GHSA-6g7w-8wpp-frhj
- rustls (crates.io) Vendor— Affected — Fixed in — No fix listed GHSA-6g7w-8wpp-frhj
CPE names CISA-ADP · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:rustls_project:rustls:*:*:*:*:*:*:*:* | — | — | Rustls Project |
- cpe:2.3:a:rustls_project:rustls:*:*:*:*:*:*:*:* Versions — — ·Rustls Project
Remediation
- Fix · CNA rustls (rustls) Fixed in 0.23.5, 0.22.4, 0.21.11
- Fix · GHSA-6g7w-8wpp-frhj rustls (crates.io) Fixed in 0.23.5 Advisory →
- Fix · GHSA-6g7w-8wpp-frhj rustls (crates.io) Fixed in 0.22.4 Advisory →
- Fix · GHSA-6g7w-8wpp-frhj rustls (crates.io) Fixed in 0.21.11 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2024-32650
- 2026-10-03 Alias added: GHSA-6g7w-8wpp-frhj
References
Other 8
- https://github.com/rustls/rustls/security/advisories/GHSA-6g7w-8wpp-frhj
- https://github.com/rustls/rustls/commit/2123576840aa31043a31b0770e6572136fbe0c2d
- https://github.com/rustls/rustls/commit/6e938bcfe82a9da7a2e1cbf10b928c7eca26426e
- https://github.com/rustls/rustls/commit/f45664fbded03d833dffd806503d3c8becd1b71e
- https://github.com/rustls/rustls/commit/5374108df698e78c3e9ef8265cac311556be24af
- https://github.com/rustls/rustls/commit/ebcb4782f23b4edf9b10a7065d9e8d4362439d9c
- https://github.com/rustls/rustls
- https://rustsec.org/advisories/RUSTSEC-2024-0336.html
More rustls vulnerabilities
- TI-2026-63063 rustls-webpki before 0.103.13 Panic via empty BIT STRING CVSS 4.0HIGH 8.7
- TI-2026-86755 Rustls accepts handshake messages at the wrong encryption level CVSS 4.0MEDIUM 6.9
- TI-2026-86753 Key exchange downgrade in rustls via unauthenticated ServerHello CVSS 4.0MEDIUM 6.3
- TI-2026-86752 Uncontrolled memory allocation in rustls Brotli certificate decompression CVSS 4.0MEDIUM 6.3
- TI-2026-86754 Application data sent to public_name server when rustls rejects ECH CVSS 4.0MEDIUM 4.6
- TI-2026-86751 Secret key material exposed through Debug formatting in Rustls CVSS 4.0MEDIUM 4.1
Sources
- CVE-2024-32650 · CVE Program
- CVE-2024-32650 · NVD
- FIRST EPSS
- GHSA-6g7w-8wpp-frhj · GitHub Advisory Database · CC BY 4.0
- CVE-2024-32650 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences