CVE-2021-22898

lowpriority · track · 14EPSS 0.045 · 91 %ileDEEUFRRUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
4.51% (91st) EPSS
CVSS 2.6 · low
Is it mine?
102 products
Check your exposure
Who says so?
9 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

curl 7.7 through 7.76.1 suffers from an information disclosure when the `-t` command line option, known as `CURLOPT_TELNETOPTIONS` in libcurl, is used to send variable=content pairs to TELNET servers. Due to a flaw in the option parser for sending NEW_ENV variables, libcurl could be made to pass on uninitialized data from a stack based buffer to the server, resulting in potentially revealing sensitive internal information to the server using a clear-text network protocol.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

3.1
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.02.6lowAV:N/AC:H/Au:N/C:P/I:N/A:Nprimary · NVD / NIST USexploitability 4.9 · impact 2.9
v3.13.1lowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:Nprimary · NVD / NIST USexploitability 1.6 · impact 1.4
v3.13.1lowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N/E:P/RL:O/RC:Csecondary · CISA US
v3.13.1lowAV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:Nsecondary · FSTEC (BDU) RU
v3.13.1lowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:Nsecondary · ENISA EU
v3.13.1lowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:Nsecondaryexploitability 1.6 · impact 1.4
v3.13.1lowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N/E:P/RL:O/RC:Csecondary · Siemens ProductCERT DE
v3.13.1lowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:Nsecondary · Phoenix Contact PSIRT DE
v3.12.9lowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: no · Technical Impact: partialcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

05

affected products (102)

Products and version ranges known to be affected.

06

advisories (11)

Vendor and ecosystem advisories describing this.

  • SSA-389290SSA-389290: Third-Party Component Vulnerabilities in SINEC INS2022-03-08csaf · siemens_psirtDE

    71 vulnerabilities in third-party components as Node.js, cURL, SQLite, CivetWeb and DNS(ISC BIND) could allow an attacker to interfere with the affected product in various ways. Siemens has released an update for SINEC INS and recommends to update to the latest versions.

  • SSA-398330SSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.52023-12-12csaf · siemens_psirtDE

    Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version >= V3.1.0 and < V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). These GNU/Linux vulnerabilities have been externally identified. Siemens has released new versions for the affected products and recommends to update to the latest versions. SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.5 are no longer maintained and there won't be any update to the CVE list anymore. Please update to the latest version. Note: This SSA advises vulnerabilities for firmware version V3.1 only; for versions < V3.1 refer to Siemens Security Bulletin SSB-439005 (https://cert-portal.siemens.com/productcert/html/ssb-439005.html).

  • VDE-2022-010PHOENIX CONTACT: Multiple Linux component vulnerabilities fixed in latest AXC F x152 LTS release2022-04-12csaf · phoenix_contact_psirtDE

    PLCnext Control AXC F x152 is certified according to IEC 62443-4-1 and IEC 62443-4-2. This certification requires that all third-party components used in the firmware are regularly checked for known vulnerabilities. Firmware components in version 2021.06 had already been updated. For the 2022.0 LTS version more firmware components have been updated implicitly fixing the vulnerabilities listed. The vulnerabilities listed above have not been individually verified in terms of actual impact and/or limitations in combination with the affected products listed. The current LTS release 2022.0 LTS contains updates of integrated third-party libraries, SDKs and other third-party software to address these issues nevertheless. UPDATE A (April 4th, 2022): Added RFC 4072 (Art. No. 1051328) and fixed affected version of AXC F 3152

  • WID-SEC-W-2022-0873cURL und libcurl: Mehrere SchwachstellenDeutsch2021-05-25csaf · cert_bundDE

    Ein lokaler Angreifer kann mehrere Schwachstellen in cURL und libcurl ausnutzen, um Informationen offenzulegen oder beliebigen Programmcode auszuführen.

  • WID-SEC-W-2023-1350Splunk Splunk Enterprise: Mehrere Schwachstellen in Komponenten von DrittanbieternDeutsch2023-06-01csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Splunk Splunk Enterprise in diversen Komponenten von Drittanbietern ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.

  • WID-SEC-W-2023-2229Splunk Splunk Enterprise: Mehrere SchwachstellenDeutsch2023-08-30csaf · cert_bundDE

    Ein entfernter, authentifizierter Angreifer kann mehrere Schwachstellen in Splunk Splunk Enterprise ausnutzen, um beliebigen Code auszuführen, einen 'Denial of Service'-Zustand zu verursachen, seine Privilegien zu erweitern und weitere, nicht spezifizierte Auswirkungen zu verursachen.

  • WID-SEC-W-2026-0180Dell Data Protection Advisor: Mehrere SchwachstellenDeutsch2026-01-20csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Dell Data Protection Advisor ausnutzen, um beliebigen Code auszuführen, einen Denial-of-Service-Zustand zu erzeugen, Sicherheitsmaßnahmen zu umgehen und nicht näher spezifizierte Angriffe zu starten.

  • ICSA-22-069-09Siemens SINEC INS2022-03-08icsa · cisa_csaf_otUS

    71 vulnerabilities in third-party components as Node.js, cURL, SQLite, CivetWeb and DNS(ISC BIND) could allow an attacker to interfere with the affected product in various ways. Siemens has released an update for SINEC INS and recommends to update to the latest versions.

  • ICSA-23-348-10Siemens SIMATIC S7-15002023-12-12icsa · cisa_csaf_otUS

    Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version >= V3.1.0 and < V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). These GNU/Linux vulnerabilities have been externally identified. Siemens has released new versions for the affected products and recommends to update to the latest versions. Note: This SSA advises vulnerabilities for firmware version V3.1 only; for versions < V3.1 refer to Siemens Security Bulletin SSB-439005 ( https://cert-portal.siemens.com/productcert/html/ssb-439005.html).

  • CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
  • CURL-CVE-2021-22898TELNET stack contents disclosure2021-05-26vendor · osvUS

    curl supports the `-t` command line option, known as `CURLOPT_TELNETOPTIONS` in libcurl. This rarely used option is used to send variable=content pairs to TELNET servers. Due to flaw in the option parser for sending `NEW_ENV` variables, libcurl could be made to pass on uninitialized data from a stack based buffer to the server. Therefore potentially revealing sensitive internal information to the server using a clear-text network protocol. This could happen because curl did not check the return code from a `sscanf(command, "%127[^,],%127s")` function invoke correctly, and would leave the piece of the send buffer uninitialized for the value part if it was provided longer than 127 bytes. The buffer used for this is 2048 bytes big and the *variable* part of the *variable=content* pairs would be stored correctly in the send buffer, making curl sending "interleaved" bytes sequences of stack contents. A single curl TELNET handshake could then be made to send off a total of around 1800 bytes of (non-contiguous) stack contents in this style: [control byte]name[control byte] stack contents [control byte]name[control byte] stack contents ... An easy proof of concept command line looks like this: curl telnet://example.com -tNEW_ENV=a,bbbbbb (256 'b's)

07

also known as (4)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

10

references (99)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan