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Public proof of conceptFix available

CVE-2023-27533

A public proof of concept exists; no exploitation attested.

  • Published2023-03-30
  • Fixed in9.0.6 · 8.2.12
  • WeaknessCWE-74 · CWE-75

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A vulnerability in input validation exists in curl <8.0 during communication using the TELNET protocol may allow an attacker to pass on maliciously crafted user name and "telnet options" during server negotiation. The lack of proper input scrubbing allows an attacker to send content or perform option negotiation without the application's intent. This vulnerability could be exploited if an application allows user input, thereby enabling attackers to execute arbitrary code on the system.

Timeline

dates in UTC
  1. 2023-03-3020:15CVE publishedNVD

Versions per branch

NVD
Splunk universal forwarder
BranchAffectedFixed in
9.0≥ 9.0.0, < 9.0.69.0.6
8.2≥ 8.2.0, < 8.2.128.2.12
9.1= 9.1.0no fix published
Fedoraproject fedora
BranchAffectedFixed in
36.x= 36no fix published
Haxx curl
BranchAffectedFixed in
7.x≥ 7.0.0, ≤ 7.881no fix published

6 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As hackerone, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • https://github.com/curl/curl
    Affected
    • = Fixed in 8.0.0no fix stated

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2023-10-11

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • cmakeAzure Linux:3all versions · fixed in 3.28.2-1
  • cmakeAzure Linux:2all versions · fixed in 3.21.4-12
  • curlUbuntu:Pro:16.04:LTSall versions · fixed in 7.47.0-1ubuntu2.19+esm8
  • curlUbuntu:Pro:14.04:LTSall versions · fixed in 7.35.0-1ubuntu2.20+esm15
  • curlUbuntu:22.04:LTSall versions · fixed in 7.81.0-1ubuntu1.10
  • curlUbuntu:20.04:LTSall versions · fixed in 7.68.0-1ubuntu2.18
  • curlUbuntu:18.04:LTSall versions · fixed in 7.58.0-2ubuntu3.24
  • curlSUSE:OpenStack Cloud Crowbar 9all versions · fixed in 7.60.0-4.56.1

67 more package ranges on OSV.dev

Vendor advisories

  • CVE-2023-27533 Red Hat Product Security86 products fixed

    curl: TELNET option IAC injection

  • ICSA-24-046-15 CISA1 known affected

    Siemens SINEC NMS

    SINEC NMS

  • SSA-943925 Siemens ProductCERT1 known affected

    SSA-943925: Multiple Vulnerabilities in SINEC NMS before V2.0 SP1

    SINEC NMS

  • ICSA-23-348-10 CISA5 known affected

    Siemens SIMATIC S7-1500

    SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) · SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) · +2 more

  • SSA-398330 Siemens ProductCERT5 known affected

    SSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.5

    SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= V3.1.0 < V3.1.5 · SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= V3.1.0 < V3.1.5 · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= V3.1.0 < V3.1.5 · +2 more

  • RHSA-2023:6679 Red Hat Product Security74 products fixed

    Red Hat Security Advisory: curl security update

2 more advisories

Full record on NVD

Fix

  1. Update Splunk universal forwarder to 9.0.6 · 8.2.12
  2. Vendor fix CISA ICSA-24-046-15 · 1 productUpdate to V2.0 SP1 or later version
  3. Vendor fix Siemens ProductCERT SSA-943925 · 1 productUpdate to V2.0 SP1 or later version
  4. Vendor fix Siemens ProductCERT SSA-398330 · 1 productUpdate to V3.1.5 or later version
  5. Vendor fix CISA ICSA-23-348-10 · 5 productsUpdate to V3.1.5 or later version
  6. Vendor fix Red Hat Product Security RHSA-2023:6679 · 74 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  7. Vendor fix Red Hat Product Security RHSA-2023:3354 · 11 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Applications using the APR libraries, such as httpd, must be restarted for this update to take effect. After installing the updated packages, the http…

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published
2023-03-30
Last Modified
2026-10-14
NVD status
Modified
GitHub Advisory
GHSA-xvw3-6q4f-2gcv

Frequently asked questions

What is CVE-2023-27533?

A vulnerability in input validation exists in curl <8.0 during communication using the TELNET protocol may allow an attacker to pass on maliciously crafted user name and "telnet options" during server negotiation. The lack of proper input scrubbing allows an attacker to send content or perform option negotiation without the application's intent. This vulnerability could be exploited if an application allows user input, thereby enabling attackers to execute arbitrary code on the system.

Is CVE-2023-27533 actively exploited?

A proof-of-concept exploit exists for CVE-2023-27533, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2023-27533?

CVE-2023-27533 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

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