CVE-2017-9798

Advisory lineage Upstream: 0 Downstream: 23
Modified
Published: 18 Sept 2017, 15:00
Last modified:04 Nov 2025, 16:09

Vulnerability Summary

Overall Risk (default)
high
59/100
CVSS Score
7.5 HIGH
v3.1 (nvd)
EPSS Score
93.84% CRITICAL
94% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
5 found
Dark Web
Not detected

Timeline

18 Sept 2017, 15:00
Published
Vulnerability first disclosed
04 Nov 2025, 16:09
Last Modified
Vulnerability information updated

Description

Apache httpd allows remote attackers to read secret data from process memory if the Limit directive can be set in a user's .htaccess file, or if httpd.conf has certain misconfigurations, aka Optionsbleed. This affects the Apache HTTP Server through 2.2.34 and 2.4.x through 2.4.27. The attacker sends an unauthenticated OPTIONS HTTP request when attempting to read secret data. This is a use-after-free issue and thus secret data is not always sent, and the specific data depends on many factors including configuration. Exploitation with .htaccess can be blocked with a patch to the ap_limit_section function in server/core.c.

CVSS Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
  • v2.0•MEDIUM•Score: 5AV:N/AC:L/Au:N/C:P/I:N/A:N

EPSS Trends

Current EPSS score: 93.84%• Percentile: 100%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • apache software foundation•apache http server

    Apache HTTP Server through 2.2.34 and 2.4.x through 2.4.27

  • Unknown•HTTP Server

    ≤ 2.2.34 | 2.4.0 | 2.4.1 | 2.4.2 | 2.4.3 | 2.4.4 | 2.4.6 | 2.4.7 | 2.4.9 | 2.4.10 | 2.4.12 | 2.4.16 | 2.4.17 | 2.4.18 | 2.4.20 | 2.4.23 | 2.4.25 | 2.4.26 | 2.4.27

  • debian•debian_linux

    7.0 | 8.0 | 9.0

References (56)