CVE-2021-39392 json
The management tool in MyLittleBackup up to and including 1.7 allows remote attackers to execute arbitrary code because machineKey is hardc…
published 2021-09-15 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-25751
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.3%
- EPSS 2.3% chance of exploitation in 30 days, percentile 83%
- public exploits
- 0
- none known
Summary
The management tool in MyLittleBackup up to and including 1.7 allows remote attackers to execute arbitrary code because machineKey is hardcoded (the same for all customers' installations) in web.config, and can be used to send serialized ASP code.
Exploit prediction
2.26% chance of exploitation in the next 30 days, higher than 83% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
References
-
mylittlebackup.com
/mlb/zip/mlb_1.7.zip
broken-link
-
gist.github.com
/omriinbar/65827626e63f15e3e50557e2d9d61281
third-party-advisory
Sources
- CVE List CVE-2021-39392
- NVD CVE-2021-39392
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.