CVE-2020-13111
NaviServer 4.99.4 to 4.99.19 allows denial of service due to the nsd/driver.c ChunkedDecode function not properly validating the length of a chunk.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
NaviServer 4.99.4 to 4.99.19 allows denial of service due to the nsd/driver.c ChunkedDecode function not properly validating the length of a chunk. A remote attacker can craft a chunked-transfer request that will result in a negative value being passed to memmove via the size parameter, causing the process to crash.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.44% probability · 73th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-20, CWE-787
- Affected
- naviserver project/naviserver
- Source
- cve@mitre.org
EPSS 1.4% since 26 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://bitbucket.org/naviserver/naviserver/commits/a5c3079f1d8996d5f34c9384a440acf3519ca3bbPatch, Third Party Advisory
- https://sourceforge.net/p/naviserver/bugs/89/Permissions Required, Third Party Advisory
- https://bitbucket.org/naviserver/naviserver/commits/a5c3079f1d8996d5f34c9384a440acf3519ca3bbPatch, Third Party Advisory
- https://sourceforge.net/p/naviserver/bugs/89/Permissions Required, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.