Vulnerability · Published Aug 10, 2021 · Assigned by mitre
CVE-2020-21677
Medium 6.5
In plain English
A medium-severity security flaw in the libsixel package (Debian). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 60% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)6.5Medium
Exploit odds (30 days)0.9%top 40.0% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
A heap-based buffer overflow in the sixel_encoder_output_without_macro function in encoder.c of Libsixel 1.8.4 allows attackers to cause a denial of service (DOS) via converting a crafted PNG file into Sixel format.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libsixel | 1.8.6-1 | DEBIAN-CVE-2020-21677 |
| Debian:13 | libsixel | 1.8.6-1 | DEBIAN-CVE-2020-21677 |
| Debian:14 | libsixel | 1.8.6-1 | DEBIAN-CVE-2020-21677 |
| Ubuntu:22.04:LTS | libsixel | no fix listed | UBUNTU-CVE-2020-21677 |
| Ubuntu:24.04:LTS | libsixel | no fix listed | UBUNTU-CVE-2020-21677 |
| Ubuntu:25.10 | libsixel | no fix listed | UBUNTU-CVE-2020-21677 |
| Ubuntu:26.04:LTS | libsixel | no fix listed | UBUNTU-CVE-2020-21677 |
| Ubuntu:26.10 | libsixel | no fix listed | UBUNTU-CVE-2020-21677 |
Affected products (as reported)
References
- https://github.com/saitoha/libsixel/issues/123 x_refsource_MISC