CVE-2021-3404
In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of...
In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of-service (and potentially code execution) due to a heap buffer overflow which can be triggered via a crafted file.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of-service (and potentially code execution) due to a heap buffer overflow which can be triggered via a crafted file.
- Record
CVE-2021-3404- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:P - Weakness
- CWE-119, CWE-787
- Updated
- 2026-11-02
CVE List No score
In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of-service (and potentially code execution) due to a heap buffer overflow which can be triggered via a crafted file.
- Record
CVE-2021-3404- Weakness
- CWE-119
- Updated
- 2026-11-02
EUVDEUVD-2021-26732 No score
In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of-service (and potentially code execution) due to a heap buffer overflow which can be triggered via a crafted file.
- Record
EUVD-2021-26732- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-5f69-j422-38p4
In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of...
In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of-service (and potentially code execution) due to a heap buffer overflow which can be triggered via a crafted file.
- Record
GHSA-5f69-j422-38p4- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-119, CWE-787
- Updated
- 2026-11-02
OSVALPINE-CVE-2021-3404
In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of-service (and potentially code execution) due to a heap buffer overflow which can be triggered via a crafted file.
- Record
ALPINE-CVE-2021-3404- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
OSV
In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of-service (and potentially code execution) due to a heap buffer overflow which can be triggered via a crafted file.
- Record
CVE-2021-3404- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-3404
In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of-service (and potentially code execution) due to a heap buffer overflow which can be triggered via a crafted file.
- Record
DEBIAN-CVE-2021-3404- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-3404
In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of-service (and potentially code execution) due to a heap buffer overflow which can be triggered via a crafted file.
- Record
UBUNTU-CVE-2021-3404- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVMGASA-2022-0316 No score
Updated ytnef packages fix security vulnerability
In ytnef 1.9.3, the TNEFSubjectHandler function in lib/ytnef.c allows remote attackers to cause a denial-of-service (and potentially code execution) due to a double free which can be triggered via a crafted file. (CVE-2021-3403) In ytnef 1.9.3, the SwapWord function in lib/ytnef.c allows remote attackers to cause a denial-of-service (and potentially code execution) due to a heap buffer overflow which can be triggered via a crafted file. (CVE-2021-3404)
- Record
MGASA-2022-0316- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
ytnefAlpine:v3.13 |
before 1.9.3-r1 | 1.9.3-r1 |
ytnefAlpine:v3.14 |
before 1.9.3-r1 | 1.9.3-r1 |
ytnefAlpine:v3.15 |
before 1.9.3-r1 | 1.9.3-r1 |
ytnefAlpine:v3.16 |
before 1.9.3-r1 | 1.9.3-r1 |
ytnefAlpine:v3.17 |
before 1.9.3-r1 | 1.9.3-r1 |
ytnefAlpine:v3.18 |
before 1.9.3-r1 | 1.9.3-r1 |
ytnefAlpine:v3.19 |
before 1.9.3-r1 | 1.9.3-r1 |
ytnefAlpine:v3.20 |
before 1.9.3-r1 | 1.9.3-r1 |
ytnefAlpine:v3.21 |
before 1.9.3-r1 | 1.9.3-r1 |
ytnefAlpine:v3.22 |
before 1.9.3-r1 | 1.9.3-r1 |
Show 14 moreShow less
| Package | Affected | Fixed |
|---|---|---|
ytnefAlpine:v3.23 |
before 1.9.3-r1 | 1.9.3-r1 |
ytnefAlpine:v3.24 |
before 1.9.3-r1 | 1.9.3-r1 |
libytnefDebian:12 |
before 1.9.3-3 | 1.9.3-3 |
libytnefDebian:13 |
before 1.9.3-3 | 1.9.3-3 |
libytnefDebian:14 |
before 1.9.3-3 | 1.9.3-3 |
ytnefMageia:8 From an advisory covering 2 CVEs |
before 2.0-1.mga8 | 2.0-1.mga8 |
libytnefUbuntu:16.04:LTS |
All versions, plus listed versions 1.5-61.5-91.5-9ubuntu0.1 |
None known |
libytnefUbuntu:18.04:LTS |
All versions, plus listed versions 1.9.2-2 |
None known |
libytnefUbuntu:20.04:LTS |
All versions, plus listed versions 1.9.3-1 |
None known |
libytnefUbuntu:22.04:LTS |
All versions, plus listed versions 1.9.3-32.0-1 |
None known |
libytnefUbuntu:24.04:LTS |
All versions, plus listed versions 2.0-12.1.2-12.1.2-1build1 |
None known |
libytnefUbuntu:25.10 |
All versions, plus listed versions 2.1.2-1build1 |
None known |
libytnefUbuntu:26.10 |
All versions, plus listed versions 2.1.2-1build2 |
None known |
libytnefUbuntu:26.04:LTS |
All versions, plus listed versions 2.1.2-1build12.1.2-1build2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected, aliases, references | OSV | |
| aliases, products | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-3404 is a high vulnerability (CVSS 7.8) in Ytnef, published March 4, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.94%, the 80th percentile. Fixed in ytnef 1.9.3-r1.