Description
A weakness has been identified in Cesanta Mongoose up to 7.20. This vulnerability affects the function handle_opt of the file /src/net_builtin.c of the component TCP Option Handler. This manipulation of the argument optlen causes infinite loop. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 7.21 is able to resolve this issue. Upgrading the affected component is advised. VulDB has contacted the vendor early and they confirmed quickly, that this issue got fixed already.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Cesanta | Mongoose | 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 7.10, 7.11, 7.12, 7.13, 7.14, 7.15, 7.16, 7.17, 7.18, 7.19, 7.20 | 7.21 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | swupdate | 2025.12+dfsg-10 | — |
| Debian 13 | swupdate | No fix yet | — |
| Debian 12 | swupdate | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | swupdate | No fix yet | — |
| Ubuntu 26.04 LTS | swupdate | No fix yet | — |
| Ubuntu 25.10 | swupdate | No fix yet | — |
| Ubuntu 24.04 LTS | swupdate | No fix yet | — |
| Ubuntu 22.04 LTS | swupdate | No fix yet | — |
References
- VDB-359528 | Cesanta Mongoose TCP Option net_builtin.c handle_opt infinite loop vdb-entry technical-description
- VDB-359528 | CTI Indicators (IOB, IOC, TTP, IOA) signature permissions-required
- Submit #796230 | Cesanta Mongoose 7.20 Denial of Service third-party-advisory
- https://github.com/dwBruijn/CVEs/blob/main/Mongoose/TCP_opt_dos.md exploit
- https://github.com/cesanta/mongoose/releases/tag/7.21 patch