CVE-2021-3694
Cross-site Scripting (XSS) - Reflected in ledgersmb/ledgersmb
LedgerSMB does not sufficiently HTML-encode error messages sent to the browser. By sending a specially crafted URL to an authenticated user, this flaw can be abused for remote code execution and information disclosure.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Cross-site Scripting (XSS) - Reflected in ledgersmb/ledgersmb
LedgerSMB does not sufficiently HTML-encode error messages sent to the browser. By sending a specially crafted URL to an authenticated user, this flaw can be abused for remote code execution and information disclosure.
- Record
CVE-2021-3694- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2021-26979
LedgerSMB does not sufficiently HTML-encode error messages sent to the browser. By sending a specially crafted URL to an authenticated user, this flaw can be abused for remote code execution and information disclosure.
- Record
EUVD-2021-26979- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-5wc4-gq9m-293h No score
LedgerSMB does not sufficiently HTML-encode error messages sent to the browser. By sending a...
LedgerSMB does not sufficiently HTML-encode error messages sent to the browser. By sending a specially crafted URL to an authenticated user, this flaw can be abused for remote code execution and information disclosure.
- Record
GHSA-5wc4-gq9m-293h- Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
LedgerSMB does not sufficiently HTML-encode error messages sent to the browser. By sending a specially crafted URL to an authenticated user, this flaw can be abused for remote code execution and information disclosure.
- Record
CVE-2021-3694- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N - CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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-79
- Updated
- 2026-11-02
OSV
LedgerSMB does not sufficiently HTML-encode error messages sent to the browser. By sending a specially crafted URL to an authenticated user, this flaw can be abused for remote code execution and information disclosure.
- Record
CVE-2021-3694- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-3694
LedgerSMB does not sufficiently HTML-encode error messages sent to the browser. By sending a specially crafted URL to an authenticated user, this flaw can be abused for remote code execution and information disclosure.
- Record
DEBIAN-CVE-2021-3694- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-3694
LedgerSMB does not sufficiently HTML-encode error messages sent to the browser. By sending a specially crafted URL to an authenticated user, this flaw can be abused for remote code execution and information disclosure.
- Record
UBUNTU-CVE-2021-3694- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N - CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUSN-5097-1 No score
ledgersmb vulnerabilities
It was discovered that LedgerSMB incorrectly handled certain inputs. An attacker could use this to leak sensitive information, cause a DoS, or execute arbitrary code. (CVE-2021-3693, CVE-2021-3694, CVE-2021-3731)
- Record
USN-5097-1- Updated
- 2026-11-02
OSVUSN-7647-1 No score
ledgersmb vulnerabilities
It was discovered that LedgerSMB did not check the origin of HTML fragments. An attacker could possibly use this issue to send a maliciously crafted URL to the server and obtain sensitive information, or execute arbitrary code. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 25.04. (CVE-2021-3693)
It was discovered that LedgerSMB did not properly encode HTML error messages. An attacker could possibly use this issue to send a maliciously crafted URL to the server and obtain sensitive information, or execute arbitrary code. This issue only affected Ubuntu 18.04 LTS. (CVE-2021-3694)
It was discovered that LedgerSMB did not guard against discrete link redirections. An attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2021-3731)
It was discovered that LedgerSMB did not properly set the 'Secure' attribute during HTTPS sessions. If a user were tricked into using an unencrypted connection, an attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 25.04. (CVE-2021-3882)
It was discovered that LedgerSMB could create admin accounts via a URL. If an admin were tricked into clicking a maliciously crafted URL, an attacker could possibly use this issue to achieve privilege escalation. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 25.04. (CVE-2024-23831)
- Record
USN-7647-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
ledgersmbDebian:12 |
before 1.6.9+ds-2.1 | 1.6.9+ds-2.1 |
ledgersmbDebian:10 From an advisory covering 3 CVEs |
before 1.6.9+ds-1+deb10u2, plus listed versions 1.6.9+ds-11.6.9+ds-1+deb10u1 |
1.6.9+ds-1+deb10u2 |
ledgersmbDebian:11 From an advisory covering 3 CVEs |
before 1.6.9+ds-2+deb11u2, plus listed versions 1.6.9+ds-21.6.9+ds-2+deb11u1 |
1.6.9+ds-2+deb11u2 |
ledgersmbUbuntu:Pro:18.04:LTS |
before 1.4.42+ds-1ubuntu0.1~esm1, plus listed versions 1.4.41+ds-11.4.42+ds-1 |
1.4.42+ds-1ubuntu0.1~esm1 |
ledgersmbUbuntu:20.04:LTS |
before 1.6.9+ds-1ubuntu0.1, plus listed versions 1.6.9+ds-1 |
1.6.9+ds-1ubuntu0.1 |
ledgersmbUbuntu:20.04:LTS From an advisory covering 3 CVEs |
before 1.6.9+ds-1ubuntu0.1, plus listed versions 1.6.9+ds-1 |
1.6.9+ds-1ubuntu0.1 |
ledgersmbUbuntu:Pro:16.04:LTS From an advisory covering 5 CVEs |
before 1.3.46-1ubuntu0.1~esm1, plus listed versions 1.3.46-1 |
1.3.46-1ubuntu0.1~esm1 |
ledgersmbUbuntu:Pro:18.04:LTS From an advisory covering 5 CVEs |
before 1.4.42+ds-1ubuntu0.1~esm1, plus listed versions 1.4.41+ds-11.4.42+ds-1 |
1.4.42+ds-1ubuntu0.1~esm1 |
ledgersmbUbuntu:Pro:20.04:LTS From an advisory covering 5 CVEs |
before 1.6.9+ds-1ubuntu0.1+esm1, plus listed versions 1.6.9+ds-11.6.9+ds-1ubuntu0.1 |
1.6.9+ds-1ubuntu0.1+esm1 |
ledgersmbUbuntu:22.04:LTS From an advisory covering 5 CVEs |
before 1.6.33+ds-1ubuntu0.1, plus listed versions 1.6.9+ds-2.11.6.33+ds-1 |
1.6.33+ds-1ubuntu0.1 |
ledgersmbUbuntu:24.04:LTS From an advisory covering 5 CVEs |
before 1.6.33+ds-2.1ubuntu0.1, plus listed versions 1.6.33+ds-2.1 |
1.6.33+ds-2.1ubuntu0.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-3694 is a high vulnerability (CVSS 8.2) in Ledgersmb, published August 23, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.51%, the 84th percentile. Fixed in ledgersmb 1.6.9+ds-2.1.
References
huntr.dev/bounties/ef7f4cf7-3a81-4516-b261-f5b6ac21430c
github.com/ledgersmb/ledgersmb/commit/98fa476d46a4a7e5e9492ed69b4fa190be5547fc
ledgersmb.org/cve-2021-3694-cross-site-scripting
debian.org/security/2021/dsa-4962
nvd.nist.gov/vuln/detail/CVE-2021-3694
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security-tracker.debian.org/tracker/CVE-2021-3694
ubuntu.com/security/CVE-2021-3694
cve.org/CVERecord?id=CVE-2021-3694