Security readout for executives and security teams
Plain-English summary
CVE-2021-4286 affects cocagne pysrp versions 1.0.0 through 1.0.16. A discrepancy in calculate_x may expose limited information. The published CVSS score is 2.6, requiring adjacent access, high complexity, and low privileges, with only low confidentiality impact. Version 1.0.17 addresses it.
Executive priority
Handle this as a low-priority dependency remediation unless pysrp is used in sensitive authentication workflows. It should be fixed during the next normal maintenance window, with faster action if affected versions appear in production identity, access, or customer-facing authentication systems.
Technical view
The issue is reported as CWE-203 in srp/_ctsrp.py, where calculate_x can leak information through observable discrepancies. Sources identify affected versions up to 1.0.16 and a fixing commit, dba52642f5e95d3da7af1780561213ee6053195f, released in pysrp 1.0.17. No source bundle evidence indicates integrity or availability impact.
Likely exposure
Exposure is limited to applications that include cocagne pysrp 1.0.0 through 1.0.16 and exercise the affected SRP code path. The CVSS vector indicates adjacent attack access, high complexity, and low privileges are required. This is dependency-level exposure, not a separately exposed network service in the provided sources.
Exploitation context
The provided bundle does not show active exploitation, and KEV is false. The CVSS vector is AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N, suggesting exploitation is constrained and mainly relevant where an attacker can interact near the affected authentication flow. Evidence is incomplete on real-world exploitability.
Researcher notes
The source bundle identifies a discrepancy-based information exposure in calculate_x, but does not include detailed exploit mechanics. Treat exploit status as unproven from these sources. Focus validation on dependency versioning, reachable SRP authentication paths, and whether the patched 1.0.17 behavior is present.
Mitigation direction
- Upgrade cocagne pysrp to version 1.0.17 or later.
- Confirm deployed environments are not pinning pysrp 1.0.16 or older.
- Review the vendor release and patch references before production rollout.
- If immediate upgrade is blocked, seek vendor guidance for temporary controls.
Validation and detection
- Inventory Python dependencies and record exact pysrp versions.
- Check lockfiles, containers, and runtime package lists for pysrp 1.0.16 or older.
- Verify whether the application exercises SRP flows using calculate_x.
- After upgrading, run authentication regression tests.
- Confirm the deployed package aligns with pysrp release 1.0.17 or later.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-203: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-4286 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Low
- CVSS
- 2.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N1.21.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
2.6LowVector: CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://vuldb.com/?id.216875CVE reference · vdb-entry, technical-description
- https://vuldb.com/?ctiid.216875CVE reference · signature, permissions-required
- https://github.com/cocagne/pysrp/pull/43CVE reference · issue-tracking
- https://github.com/cocagne/pysrp/commit/dba52642f5e95d3da7af1780561213ee6053195fCVE reference · patch
- https://github.com/cocagne/pysrp/releases/tag/1.0.17CVE reference · patch
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Observable Discrepancy
Observable Discrepancy represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.