CVE-2019-5885
Matrix Synapse Predictable Secret Key
Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other secrets which could allow remote attackers to impersonate users.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other secrets which could allow remote attackers to impersonate users.
- Record
CVE-2019-5885- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:P/A:N - Weakness
- CWE-330
- Updated
- 2026-11-02
CVE List No score
Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other secrets which could allow remote attackers to impersonate users.
- Record
CVE-2019-5885- Updated
- 2026-11-02
EUVDEUVD-2019-0084 No score
Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other secrets which could allow remote attackers to impersonate users.
- Record
EUVD-2019-0084- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-jrqm-v8cv-53ww
Matrix Synapse Predictable Secret Key
Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other secrets which could allow remote attackers to impersonate users.
- Record
GHSA-jrqm-v8cv-53ww- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-330
- Updated
- 2026-11-02
OSV
Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other secrets which could allow remote attackers to impersonate users.
- Record
CVE-2019-5885- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2019-5885
Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other secrets which could allow remote attackers to impersonate users.
- Record
DEBIAN-CVE-2019-5885- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
Show 5 moreShow less
OSVGHSA-jrqm-v8cv-53ww
Matrix Synapse Predictable Secret Key
Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other secrets which could allow remote attackers to impersonate users.
- Record
GHSA-jrqm-v8cv-53ww- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-330
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2019-5885
Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other secrets which could allow remote attackers to impersonate users.
- Record
UBUNTU-CVE-2019-5885- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2024:11041-1 No score
matrix-synapse-1.43.0-1.1 on GA media
These are all security issues fixed in the matrix-synapse-1.43.0-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:11041-1- Updated
- 2026-11-02
OSVPYSEC-2019-187 No score
Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other secrets which could allow remote attackers to impersonate users.
- Record
PYSEC-2019-187- Updated
- 2026-11-02
OSVUSN-6076-1 No score
matrix-synapse vulnerabilities
It was discovered that Synapse incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to cause a denial of service. (CVE-2019-18835, CVE-2018-12291, CVE-2018-10657)
It was discovered that Synapse incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to hijack the session. (CVE-2019-11842, CVE-2018-12423)
It was discovered that Synapse incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to perform spoofing or user impersonation. (CVE-2019-5885, CVE-2018-16515)
- Record
USN-6076-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
matrix-synapsePyPI |
before 0.34.0.1 | 0.34.0.1 |
matrix-synapsePyPI |
before 0.34.0.1, plus listed versions 0.33.50.33.5.10.33.60.33.6rc10.33.7 Show 8 moreShow less0.33.7rc10.33.7rc20.33.80.33.8rc20.33.90.34.00.34.0rc10.34.0rc2 |
0.34.0.1 |
matrix-synapseUbuntu:Pro:18.04:LTS |
before 0.24.0+dfsg-1ubuntu0.1~esm1, plus listed versions 0.19.2+dfsg-60.24.0+dfsg-1 |
0.24.0+dfsg-1ubuntu0.1~esm1 |
matrix-synapseUbuntu:Pro:18.04:LTS From an advisory covering 7 CVEs |
before 0.24.0+dfsg-1ubuntu0.1~esm1, plus listed versions 0.19.2+dfsg-60.24.0+dfsg-1 |
0.24.0+dfsg-1ubuntu0.1~esm1 |
matrix-synapseopenSUSE:Tumbleweed From an advisory covering 11 CVEs |
before 1.43.0-1.1 | 1.43.0-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected | ||
| 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-2019-5885 is a high vulnerability (CVSS 7.5) in Matrix Synapse, published March 19, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.48%, the 84th percentile. Fixed in matrix-synapse 0.34.0.1.
References
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/32Y6KD3OAHCG5P33HC2QEX3NUZOSXCGZ
matrix.org/blog/2019/01/10/critical-security-update-synapse-0-34-0-1-synapse-0-34-1-1
nvd.nist.gov/vuln/detail/CVE-2019-5885
github.com/matrix-org/synapse/issues/4664
Show 29 moreShow less
security-tracker.debian.org/tracker/CVE-2019-5885
ubuntu.com/security/CVE-2019-5885
cve.org/CVERecord?id=CVE-2019-5885
suse.com/security/cve/CVE-2018-12291