CVE-2020-1917 json
xbuf_format_converter, used as part of exif_read_data, was appending a terminating null character to the generated string, but was not usin…
published 2021-03-10 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-12738
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.4%
- EPSS 1.4% chance of exploitation in 30 days, percentile 72%
- public exploits
- 0
- none known
Summary
xbuf_format_converter, used as part of exif_read_data, was appending a terminating null character to the generated string, but was not using its standard append char function. As a result, if the buffer was full, it would result in an out-of-bounds write. This issue affects HHVM versions prior to 4.56.3, all versions between 4.57.0 and 4.80.1, all versions between 4.81.0 and 4.93.1, and versions 4.94.0, 4.95.0, 4.96.0, 4.97.0, 4.98.0.
Patch / fix
Exploit prediction
1.38% chance of exploitation in the next 30 days, higher than 72% 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 |
Affected products
- Facebook HHVM
Classification
References
-
github.com
/facebook/hhvm/commit/08193b7f0cd3910256e00d599f0f3eb2519c44ca
patch, third-party-advisory
-
hhvm.com
/blog/2021/02/25/security-update.html
release-notes, vendor-advisory
Sources
- CVE List CVE-2020-1917
- NVD CVE-2020-1917
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.