CVE-2020-1917
xbuf_format_converter, used as part of exif_read_data, was appending a terminating null character to the generated string, but was not…
- Published
- Updated
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- Assigned by
Description
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.
Timeline
ID reserved
By facebook
- 15 months later
· 15 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.4% · top 28% of all CVEs (8 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Weakness
Affected products
- unaffected 4.98.1 – < unspecified
- affected 4.98.0
- unaffected 4.97.1 – < unspecified
- affected 4.97.0
- unaffected 4.96.1 – < unspecified
- affected 4.96.0
- unaffected 4.95.1 – < unspecified
- affected 4.95.0
- unaffected 4.94.1 – < unspecified
- affected 4.94.0
- unaffected 4.93.2 – < unspecified
- affected 4.81.0 – < unspecified
- unaffected 4.80.2 – < unspecified
- affected 4.57.0 – < unspecified
- unaffected 4.56.3 – < unspecified
- affected unspecified – < 4.56.3
References (2)
- https://hhvm.com/blog/2021/02/25/security-update.html (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/facebook/hhvm/commit/08193b7f0cd3910256e00d599f0f3eb2519c44ca (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2020-1917)Record last updated .