CVE-2018-20355
An invalid write of 8 bytes due to a use-after-free vulnerability in the mg_http_free_proto_data_cgi function call in mongoose.c in Cesanta Mongoose Embedded Web Server Library 6.13 and earlier allows a denial of service (application crash) or remote…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.57%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
An invalid write of 8 bytes due to a use-after-free vulnerability in the mg_http_free_proto_data_cgi function call in mongoose.c in Cesanta Mongoose Embedded Web Server Library 6.13 and earlier allows a denial of service (application crash) or remote code execution.
- CVSS 3.0
- 9.8 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 3.57% probability · 89th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- cesanta/mongoose
- Source
- cve@mitre.org
EPSS 3.6% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/insi2304/mongoose-6.13-fuzz/blob/master/Simplest_Web_Server_Use_After_Free-mg_http_free_proto_data_cgi.pngExploit, Third Party Advisory
- https://github.com/insi2304/mongoose-6.13-fuzz/blob/master/Simplest_Web_Server_Use_After_Free-mg_http_free_proto_data_cgi.pngExploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.