CVE-2021-22901
curl 7.75.0 through 7.76.1 suffers from a use-after-free vulnerability resulting in already freed memory being used when a TLS 1.3 session ticket arrives over a connection. A malicious server can use
02 Description
curl 7.75.0 through 7.76.1 suffers from a use-after-free vulnerability resulting in already freed memory being used when a TLS 1.3 session ticket arrives over a connection. A malicious server can use
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 63.53% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 99.2% of scored records. A rank, not a probability.
- NVD base score
- 8.1 (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:H/I:H/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-10-14.
- Red Hat severity
- Important. 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
- 2021-06-11 15:49Z5 YR AGO
- Last updated
- 2026-10-14 10:31Z15 DAYS AGO
- Reserved
- 2021-01-06
- Assigning CNA
- hackerone
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-416Use After FreeVariant
- Data version
- 5.2
- Document digest
- 6ea5ba92ce8aaaf5fdb7cbdf00c06ddfd271e917da93afb3601ea99035106cca
05 Affected products
06 References
- hackerone.comhttps://hackerone.com/reports/1180380
- curl.sehttps://curl.se/docs/CVE-2021-22901.html
- github.comhttps://github.com/curl/curl/commit/7f4a9a9b2a49547eae24d2e19bc5c346e9026479
- www.oracle.comhttps://www.oracle.com//security-alerts/cpujul2021.html
- security.netapp.comhttps://security.netapp.com/advisory/ntap-20210723-0001/
- www.oracle.comhttps://www.oracle.com/security-alerts/cpujan2022.html
- security.netapp.comhttps://security.netapp.com/advisory/ntap-20210727-0007/
- www.oracle.comhttps://www.oracle.com/security-alerts/cpuapr2022.html
- cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
- cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-732250.pdf
- cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-389290.html
- cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-732250.html
- cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-398330.html
07 Fixed in
Arch Linux
- curl Fixed in 7.77.0-1
- lib32-curl Fixed in 7.77.0-1
- lib32-libcurl-compat Fixed in 7.77.0-1
- libcurl-compat Fixed in 7.77.0-1
Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.