CVE-2023-41335 | Temporary storage of plaintext passwords during password changes in matrix synapse

Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. When users update their passwords, the new credentials may be briefly held in the server database. While this doesn't grant the server any added capabilities—it already learns the users' passwords as part of the authentication process—it does disrupt the expectation that passwords won't be stored in the database. As a result, these passwords could inadvertently be captured in database backups for a longer duration. These temporarily stored passwords are automatically erased after a 48-hour window. This issue has been addressed in version 1.93.0. Users are advised to upgrade. There are no known workarounds for this issue.

Published: 2023-09-27 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-41335 is rated Low Risk (25.2/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.11%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-41335

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-01 0.16% 0.11% -0.05%
2 2026-03-07 0.06% 0.16% +0.10%
3 2023-10-06 — 0.06% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-41335

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.7 3.1 LOW
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 0.6 2.7 [email protected]
3.7 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 1.2 2.5 [email protected]

Weakness enumeration for CVE-2023-41335

GitHub Security Advisory for CVE-2023-41335

GHSA-4f74-84v3-j9q5 · Severity: low · Ecosystem: pip — matrix-synapse vulnerable to temporary storage of plaintext passwords during password changes

OS Trackers for CVE-2023-41335

vendor priority summary link
alpine — CVE-2023-41335: 1 source package rows (synapse); 14 state rows across 6 repos (3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 6, open 8. https://security.alpinelinux.org/vuln/CVE-2023-41335
debian not yet assigned CVE-2023-41335 not yet assigned priority: Debian including 1 source packages (matrix-synapse), 2 status rows across 2 suites (forky, sid): resolved 2. https://security-tracker.debian.org/tracker/CVE-2023-41335
gentoo low CVE-2023-41335: 1 GLSA(s) (202401-12), 1 atom(s) (net-im/synapse); latest impact low. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-41335
ubuntu medium CVE-2023-41335 medium priority: Ubuntu including 1 source packages (matrix-synapse), 10 status rows across 10 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, trusty, upstream, xenial): ignored 4, not-affected 4, released 2. https://ubuntu.com/security/CVE-2023-41335

Affected software / configurations for CVE-2023-41335

Vendor Product Version Raw CPE
matrix synapse >= 1.66.0, < 1.93.0 cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*
fedoraproject fedora 37 cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*
fedoraproject fedora 38 cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*

References for CVE-2023-41335

cvelogic Threat Intelligence