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CVE Record

CVE-2021-23803: Access Control Bypass

This affects the package latte/latte before 2.10.6. There is a way to bypass allowFunctions that will affect the security of the application. When the template is set to allow/disallow the use of certain functions, adding control characters (x00-x08) after the function will bypass these restrictions.

CriticalCVSS 9.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

CVE-2021-23803 lets a restricted Latte template use functions that an application intended to block. If an exposed application lets users or administrators edit templates, this could undermine confidentiality, integrity, and availability protections.

Executive priority

Prioritize patching if Latte templates are editable by customers, tenants, CMS users, or lower-trust administrators. If templates are fully developer-controlled, urgency is lower but still important because the vulnerable dependency weakens a security control.

Technical view

latte/latte before 2.10.6 has an allowFunctions bypass. Sources state control characters after a function name can bypass configured allow or deny restrictions, affecting applications relying on Latte template function controls as a security boundary.

Likely exposure

Exposure is likely limited to PHP applications using latte/latte before 2.10.6, especially where templates are user-editable, tenant-editable, CMS-managed, or otherwise not fully trusted.

Exploitation context

The source bundle does not show CISA KEV listing or confirmed active exploitation. The supplied CVSS is 9.8 with network attack vector, low complexity, no privileges, no user interaction, and proof-of-concept exploit maturity.

Researcher notes

The public description is specific about the bypass mechanism but sparse on real-world exploit use and impacted application patterns. Validate exposure through dependency version, template trust model, and reliance on allowFunctions, rather than assuming all Latte use is equally exploitable.

Mitigation direction

  • Upgrade latte/latte to version 2.10.6 or later.
  • Check vendor guidance and the upstream commit before relying on compensating controls.
  • Restrict template editing to trusted administrators until patched.
  • Review applications that treat allowFunctions as a security boundary.
  • Audit dependency manifests and deployed artifacts for vulnerable Latte versions.

Validation and detection

  • Check composer.lock or SBOM entries for latte/latte versions before 2.10.6.
  • Identify code paths configuring Latte allowFunctions or function deny behavior.
  • Confirm whether any untrusted users can create or modify templates.
  • Verify production deployments run the patched dependency, not only source branches.
  • Review security scanner results against the cited Snyk advisory and CVE record.
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-2021-23803 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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
9.8CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P3.95.9Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

9.8Critical
CVSS 3.1 vector shape for CVE-2021-23803Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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/alatte/latteunspecifiedListed
Weakness

CWE details

No CWE listed

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