CVE-2020-21677: saitoha libsixel Out-of-bounds Write
CVSS: 6.5v3.1MediumModified
AliasesUBUNTU-CVE-2020-21677DEBIAN-CVE-2020-21677
Published 10-08-2021Last modified 04-08-2024
Vulnerability summary
CVE-2020-21677 is a medium (CVSS 6.5) Out-of-bounds Write vulnerability in saitoha libsixel. EPSS estimates a 0.90% chance of exploitation in the next 30 days, higher than 59.1% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
6.5/10
010
Medium · v3.1 (NVD)EPSS score
0.90%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github
Timeline
- 10-08-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 3 sources · 2 versionsMedium 6.5Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Medium 4.3Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:N/I:N/A:PSourcesSingle source
EPSS trend
Probability
0.90%
Chance of exploitation in the next 30 days
Percentile
59%
Versus all other CVEs
30-day change
0.00 pp
From 0.90% on 19-09-2026
19-09-202619-10-2026
EPSS score0.90%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundLibsixel
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Debian1 product
- libsixel< 1.8.6-1
Saitoha1 product
- libsixel1.8.4
Ubuntu1 product
- libsixelAll versions (No fix recorded)
3 vendors · 3 products
References
4 links- github.com/saitoha/libsixel/issues/123X Refsource MISCREPORTExploitIssue TrackingPatchThird Party Advisory
