Buffer overflow in Apache HTTP Server
CVE-2021-39275
ap_escape_quotes() may write beyond the end of a buffer when given malicious input. No included modules pass untrusted data to these functions, but third-party / external modules may. This issue affects Apache HTTP Server 2.4.48 and earlier.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.394 (98.6th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 99th percentile — 98.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.394 · newest: 0.394 · change: 0.000
Affected products
- Apache HTTP Server
- Apache Software Foundation HTTP Server — versions Apache HTTP Server 2.4
- NetApp Cloud Backup
- NetApp Clustered Data Ontap
- NetApp Storagegrid
- Oracle HTTP Server — versions 12.2.1.3.0, 12.2.1.4.0
- Oracle Instantis Enterprisetrack — versions 17.1, 17.2, 17.3
- Oracle Zfs Storage Appliance Kit — versions 8.8
- Siemens Sinec Nms
- Siemens Sinema Server — versions 14.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- httpd.apache.org/security/vulnerabilities_24.html (Release Notes, Vendor Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory, Third Party Advisory)
- lists.apache.org/thread.html/r82838efc5fa6fc4c73986399c9b71573589f78b31846aff5b… (mailing-list, Patch)
- lists.apache.org/thread.html/r82c077663f9759c7df5a6656f925b3ee4f55fcd33c889ba7c… (mailing-list, Patch)
- lists.apache.org/thread.html/r3925e167d5eb1c75def3750c155d753064e1d34a143028bb3… (mailing-list, Patch)
- lists.apache.org/thread.html/r61fdbfc26ab170f4e6492ef3bd5197c20b862ce156e9d5a54… (mailing-list, Patch)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2021/10/msg00001.html (mailing-list, Mailing List, Third Party Advisory)
- www.debian.org/security/2021/dsa-4982 (vendor-advisory, Third Party Advisory)
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-h… (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-39275?
- CVE-2021-39275 is a critical-severity vulnerability in Apache HTTP Server, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2021-09-16.
- How severe is CVE-2021-39275?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2021-39275 known to be exploited?
- 17 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.