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CVE Record

CVE-2020-7731: Denial of Service (DoS)

This affects all versions <0.7.0 of package github.com/russellhaering/gosaml2. There is a crash on nil-pointer dereference caused by sending malformed XML signatures.

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2020-7731 is a denial-of-service issue in the Go SAML library github.com/russellhaering/gosaml2 before 0.7.0. Malformed XML signatures can trigger a nil-pointer crash, potentially interrupting applications that rely on this library for SAML authentication.

Executive priority

Treat this as a high-priority availability risk for internet-facing SAML login services. It does not indicate data theft, but a crash in authentication can block users and disrupt business access.

Technical view

The vulnerability is a nil-pointer dereference during XML signature handling in gosaml2 versions before 0.7.0. CVSS 3.1 rates it 7.5 high: network reachable, low complexity, no privileges, no user interaction, with availability impact only.

Likely exposure

Exposure is likely in Go applications that import github.com/russellhaering/gosaml2 before version 0.7.0 and expose SAML login, assertion consumer, or metadata-processing paths to users or identity providers.

Exploitation context

The source bundle does not show KEV listing or cited evidence of active exploitation. The plausible abuse case is remote crash-triggering input against SAML XML signature processing, causing service disruption where vulnerable code is reachable.

Researcher notes

Evidence identifies a malformed XML signature crash in gosaml2 before 0.7.0, with issue and release references. The bundle provides no CWE, no exploit-in-the-wild evidence, and no details beyond denial of service from nil-pointer dereference.

Mitigation direction

  • Upgrade github.com/russellhaering/gosaml2 to version 0.7.0 or later.
  • Check vendor release notes and issue 59 for project-specific guidance.
  • Prioritize externally reachable SAML authentication services first.
  • Add dependency scanning to detect older gosaml2 versions.
  • Review crash monitoring around SAML request handling.

Validation and detection

  • Inspect go.mod and go.sum for github.com/russellhaering/gosaml2 versions below 0.7.0.
  • Confirm deployed artifacts use the upgraded dependency, not only source control.
  • Inventory services exposing SAML endpoints backed by this library.
  • Review application logs for nil-pointer panics during SAML XML signature processing.
  • Run existing authentication regression tests after upgrading.
Prepared
Confidence
high
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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

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CVE-2020-7731 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P3.93.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2020-7731Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/agithub.com/russellhaering/gosaml20Listed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.