01 Record

CVE-2021-22924

libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse, if one of them matches the setup.Due to errors in the logic, the config matching function did not take

LowPUBLISHEDCNA: hackerone

CNA base score3.7 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

View raw JSON

02 Description

libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse, if one of them matches the setup.Due to errors in the logic, the config matching function did not take

03 Exploitation and scoring

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

6.27% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 92.9% of scored records. A rank, not a probability.

NVD base score

3.7 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2021-08-05 20:16Z5 YR AGO

Last updated

2025-06-09 15:02Z1 YR AGO

Reserved

2021-01-06

Assigning CNA

hackerone

Record state

PUBLISHED

Severity

Low (CVSS 3.7)

CNA CVSS vector

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

Weaknesses

CWE-20Improper Input ValidationClass
CWE-706Use of Incorrectly-Resolved Name or ReferenceClass
CWE-295Improper Certificate ValidationBase

Data version

5.1

Document digest

2877b2d1cda82923d2ac67b1030fffca67b2d9b2a03681991527b2744e00876b

05 Affected products

VendorProductVersionsPlatforms

n/ahttps://github.com/curl/curlcurl 7.10.4 to and include curl 7.77.0—

06 References

hackerone.comhttps://hackerone.com/reports/1223565x_refsource_MISC
lists.fedoraproject.orgFEDORA-2021-5d21b90a30https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FRUCW2UVNYUDZF72DQLFQR4PJEC6CF7V/vendor-advisoryx_refsource_FEDORA
lists.debian.org[debian-lts-announce] 20210813 [SECURITY] [DLA 2734-1] curl security updatehttps://lists.debian.org/debian-lts-announce/2021/08/msg00017.htmlmailing-listx_refsource_MLIST
lists.apache.org[kafka-dev] 20210831 Security vulnerabilities in kafka:2.13-2.6.0/2.7.0 docker imagehttps://lists.apache.org/thread.html/r61db8e7dcb56dc000a5387a88f7a473bacec5ee01b9ff3f55308aacc%40%3Cdev.kafka.apache.org%3Emailing-listx_refsource_MLIST
lists.apache.org[kafka-users] 20210831 Security vulnerabilities in kafka:2.13-2.6.0/2.7.0 docker imagehttps://lists.apache.org/thread.html/r61db8e7dcb56dc000a5387a88f7a473bacec5ee01b9ff3f55308aacc%40%3Cusers.kafka.apache.org%3Emailing-listx_refsource_MLIST
lists.apache.org[kafka-users] 20210901 Re: [EXTERNAL] Re: Security vulnerabilities in kafka:2.13-2.6.0/2.7.0 docker imagehttps://lists.apache.org/thread.html/rbf4ce74b0d1fa9810dec50ba3ace0caeea677af7c27a97111c06ccb7%40%3Cusers.kafka.apache.org%3Emailing-listx_refsource_MLIST
lists.apache.org[kafka-dev] 20210901 Re: [EXTERNAL] Re: Security vulnerabilities in kafka:2.13-2.6.0/2.7.0 docker imagehttps://lists.apache.org/thread.html/rbf4ce74b0d1fa9810dec50ba3ace0caeea677af7c27a97111c06ccb7%40%3Cdev.kafka.apache.org%3Emailing-listx_refsource_MLIST
www.oracle.comhttps://www.oracle.com/security-alerts/cpuoct2021.htmlx_refsource_MISC
security.netapp.comhttps://security.netapp.com/advisory/ntap-20210902-0003/x_refsource_CONFIRM
www.oracle.comhttps://www.oracle.com/security-alerts/cpujan2022.htmlx_refsource_MISC
cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdfx_refsource_CONFIRM
cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-732250.pdfx_refsource_CONFIRM
cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdfx_refsource_CONFIRM
www.debian.orgDSA-5197https://www.debian.org/security/2022/dsa-5197vendor-advisoryx_refsource_DEBIAN
lists.debian.org[debian-lts-announce] 20220828 [SECURITY] [DLA 3085-1] curl security updatehttps://lists.debian.org/debian-lts-announce/2022/08/msg00017.htmlmailing-listx_refsource_MLIST

01 Record index

CVE-2021-22924

02 Description

03 Exploitation and scoring

04 Metadata

05 Affected products

06 References

02 Records

CVE-2021-22924

02 Description

03 Exploitation and scoring

04 Metadata

05 Affected products

06 References