GHSA-jrqm-v8cv-53ww CVE-2019-5885 PYSEC-2019-187
Matrix Synapse Predictable Secret Key
High
PyPI
- Severity
- 0.0 / 10
- High · CVSS 4.0
- Exploit chance (EPSS)
- 2.44%
- Chance of exploitation in the next 30 days. Higher than 84.30% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-330 Use of Insufficiently Random Values
- Fix
0.34.0.1- Upgrade matrix-synapse to this version or later
Description
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.
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| matrix-synapse | < 0.34.0.1 |
0.34.0.1 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
matrix-synapse PyPI → 0.34.0.1
- pip
pip install --upgrade "matrix-synapse>=0.34.0.1"- poetry
poetry add "matrix-synapse>=0.34.0.1"- uv
uv add "matrix-synapse>=0.34.0.1"
Severity breakdown
CVSS 4.0 0.0
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
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- High
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
CVSS 3.0 7.5
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Weakness
CWE-330: Use of Insufficiently Random Values
The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.
How to prevent it
- Architecture and Design: Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds. In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts. Pseudo-random number generators can produce predictable numbers if the generator is known and the seed can be guessed. A 256-bit seed is a good starting point for producing a "random enough" number.
- Implementation: Consider a PRNG that re-seeds itself as needed from high quality pseudo-random output sources, such as hardware devices.
- Architecture and Design, Requirements: Use products or modules that conform to FIPS 140-2 [REF-267] to avoid obvious entropy problems. Consult FIPS 140-2 Annex C ("Approved Random Number Generators").
References
Advisories
Write-ups
Packages
Other links
- github.com/matrix-org/synapse/issues/4664
- github.com/matrix-org/synapse/pull/4315
- github.com/matrix-org/synapse/pull/4373
- github.com/matrix-org/synapse/blob/67f9e5293ea6650b2ec284c0b7503f3f3eade94b/doc…
- github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2019-187…
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/32Y6K…
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VMCLO…
- matrix.org/blog/2019/01/10/critical-security-update-synapse-0-34-0-1-synapse-0-…
- matrix.org/blog/2019/01/15/further-details-on-critical-security-update-in-synap…
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VMCLO…
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/32Y6K…
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-6qf2-7x63-mm6v Synapse pagination Denial of Service | Low | Also affects matrix-synapse |
| GHSA-8q93-326v-3m7g Synapse CPU starvation (Denial of Service) | Medium | Also affects matrix-synapse |
| GHSA-fh66-fcv5-jjfr Synapse's invalid device keys degrade federation functionality | Medium | Also affects matrix-synapse |
| GHSA-v56r-hwv5-mxg6 Synapse vulnerable to federation denial of service via malformed events | High | Also affects matrix-synapse |
| GHSA-56w4-5538-8v8h Synapse Matrix has a partial room state leak via Sliding Sync | Medium | Also affects matrix-synapse |
| GHSA-vp6v-whfm-rv3g Synapse can be forced to thumbnail unexpected file formats, invoking external, potentially untrustworthy decoders | Critical | Also affects matrix-synapse |
| GHSA-f3r3-h2mq-hx2h Synapse allows a a malformed invite to break the invitee's `/sync` | Medium | Also affects matrix-synapse |
| GHSA-rfq8-j7rh-8hf2 Synapse allows unsupported content types to lead to memory exhaustion | High | Also affects matrix-synapse |
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