CVE-2020-5217Public exploitNetwork attack vector

CSP weakening via unescaped directive semicolons

Published Jan 23, 2020 · Updated Aug 4, 2024

Directive injection in Twitter secure_headers before 3.8.0, 5.0.0 through 5.0.5, and 6.0.0 through 6.1.2 allows attackers to weaken CSP. The append_content_security_policy_directives and override_content_security_policy_directives paths serialize untrusted values without neutralizing semicolons, allowing a value to start a new directive. Exploitation requires a consuming application to pass attacker-controlled input into either API; an injected directive can supersede an intended script-src policy or enable a directive marked OPT_OUT.

CVSS severity4.4
Medium
EPSS probability1.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Directive injection in Twitter secure_headers before 3.8.0, 5.0.0 through 5.0.5, and 6.0.0 through 6.1.2 allows attackers to weaken CSP. The append_content_security_policy_directives and override_content_security_policy_directives paths serialize untrusted values without neutralizing semicolons, allowing a value to start a new directive. Exploitation requires a consuming application to pass attacker-controlled input into either API; an injected directive can supersede an intended script-src policy or enable a directive marked OPT_OUT.

The record

CVE
CVE-2020-5217
Published
Jan 23, 2020
Updated
Aug 4, 2024
Vendor
Twitter
Product
secure_headers
Classifications
CWE-74, CWE-95
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 23, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.8.0
  2. Affected versionversion=>= 5.0.0, < 5.1.0
  3. Affected versionversion=>= 6.0.0, < 6.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Twitter · secure_headersversion=< 3.8.0; version=>= 5.0.0, < 5.1.0; version=>= 6.0.0, < 6.2.0

Published CVSS scores

4.4GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N
5.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
CWE-95Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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