Vulnerability in Akka HTTP Server
CVE-2021-42697
Akka HTTP 10.1.x before 10.1.15 and 10.2.x before 10.2.7 can encounter stack exhaustion while parsing HTTP headers, which allows a remote attacker to conduct a Denial of Service attack by sending a User-Agent header with deeply nested comments.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.361 (98.4th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 98th percentile — 98.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.361 · newest: 0.361 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- akka.io/blog/ (Vendor Advisory)
- doc.akka.io/docs/akka-http/current/security/2021-CVE-2021-42697-stack-overflow-… (Vendor Advisory)
- akka.io/blog/news/2021/11/02/akka-http-10.2.7-released (Release Notes, Vendor Advisory)
- akka.io/blog/news/2021/11/22/akka-http-10.1.15-released (Release Notes, Vendor Advisory)
- packetstormsecurity.com/files/167018/Akka-HTTP-10.1.14-Denial-Of-Service.html (Exploit, VDB Entry, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-42697?
- CVE-2021-42697 is a high-severity vulnerability in Akka HTTP Server, classified under Uncontrolled Recursion. CVSS score: 7.5/10. Published 2021-11-02.
- How severe is CVE-2021-42697?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2021-42697 known to be exploited?
- 11 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.