ESP-IDF: Stack-based memory corruption in lwIP DNS/SNTP handling for multi-IP DNS responses
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
ESP-IDF is the Espressif Internet of Things (IOT) Development Framework. From 5.2.3 until 5.3.7, 5.4.5, 5.5.6, and 6.0.3, the lwIP DNS resolver's cached-lookup path in dns_lookup() in dns.c copies every cached address into a caller-provided single ip_addr_t output buffer without a length parameter or bounds check. When CONFIG_LWIP_DNS_MAX_HOST_IP is greater than 1 and a cached hostname has multiple A or AAAA records, a subsequent lookup through dns_gethostbyname() or dns_gethostbyname_addrtype() writes beyond the single-element buffer into adjacent stack memory. A network-positioned attacker who influences DNS responses can cause a reboot through stack-canary corruption or, without stack protection, overwrite stack variables with attacker-controlled address bytes and potentially redirect control flow. This issue is fixed in versions 5.5.6 and 6.0.3 and is scheduled to be fixed in versions 5.3.7 and 5.4.5. No fixed release is available for the end-of-life 5.2 line.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| espressif | esp-idf | 5.2.3 – 5.2.8; 5.3.2 to before 5.3.7; 5.4.0 to before 5.4.5; 5.5.0 to before 5.5.6; 6.0.0 to before 6.0.3 | 5.3.7, 5.4.5, 5.5.6, 6.0.3 | Patch available | CNA |
- esp-idf Vendorespressif Affected 5.2.3 – 5.2.8; 5.3.2 to before 5.3.7; 5.4.0 to before 5.4.5; 5.5.0 to before 5.5.6; 6.0.0 to before 6.0.3 Fixed in 5.3.7, 5.4.5, 5.5.6, 6.0.3 Patch available CNA
Remediation
- Fix · CNA esp-idf (espressif) Fixed in 5.3.7, 5.4.5, 5.5.6, 6.0.3
Timeline
- 2026-11-04 Threatist record created from CVE-2026-113783
- 2026-11-06 Priority changed: MEDIUM → LOW
References
Other 7
- https://github.com/espressif/esp-idf/security/advisories/GHSA-ch63-jxm5-vmvf
- https://github.com/espressif/esp-idf/commit/75f2ff7e0c2d19e113293ec122b701c83d2f6665
- https://github.com/espressif/esp-idf/commit/7ab85eb4dc7d7695960d940badcd62592c365056
- https://github.com/espressif/esp-idf/commit/882843dbf838b0c02e09d46bb6283bda73496b8c
- https://github.com/espressif/esp-idf/commit/98e6e7a08fca391563651a1e751cc45a3b27d18b
- https://github.com/espressif/esp-idf/commit/af7543d00a4d7b489e010a70b59fd3d8022a40f4
- https://github.com/espressif/esp-idf/commit/defaa2f559470acfee5e2e5ea80a79b73424d483
More espressif vulnerabilities
- TI-2026-31061 arduino-esp32: Stack buffer overflow in WebServer multipart boundary parsing leads to remote crash potential RCE CVSS 3.1CRITICAL 9.8
- TI-2024-30765 Multiple Poisoned Pipeline Execution (PPE) vulnerabilities CVSS 3.1CRITICAL 10.0
- TI-2026-30028 Improper validation of NBNS name_len in arduino-esp32 NetBIOS leads to memory corruption CVSS 3.1HIGH 8.8
- TI-2025-33484 CSRF Vulnerability in Firmware Update Endpoints Allows Remote Code Execution CVSS 4.0HIGH 8.7
- TI-2024-22076 Buffer Overflow vulnerability in esp-idf v.5.1 allows a remote attacker to execute… CVSS 3.1MEDIUM 6.5
- TI-2025-33011 arduino-esp32 vulnerable to CRLF injection in WebServer.cpp CVSS 4.0HIGH 8.9
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences