httpd: SetEnvIf resource exhaustion
Published Nov 8, 2011
1.2
LOWCVSS 2.0
EPSS 3.02%
Description
The ap_pregsub function in server/util.c in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x through 2.2.21, when the mod_setenvif module is enabled, does not restrict the size of values of environment variables, which allows local users to cause a denial of service (memory consumption or NULL pointer dereference) via a .htaccess file with a crafted SetEnvIf directive, in conjunction with a crafted HTTP request header, related to (1) the "len +=" statement and (2) the apr_pcalloc function call, a different vulnerability than CVE-2011-3607.
Affected products
No data.
Configuration 1
- 2.0
- 2.0.9
- 2.0.28
- 2.0.28
- 2.0.32
- 2.0.32
- 2.0.34
- 2.0.35
- 2.0.36
- 2.0.37
- 2.0.38
- 2.0.39
- 2.0.40
- 2.0.41
- 2.0.42
- 2.0.43
- 2.0.44
- 2.0.45
- 2.0.46
- 2.0.47
- 2.0.48
- 2.0.49
- 2.0.50
- 2.0.51
- 2.0.52
- 2.0.53
- 2.0.54
- 2.0.55
- 2.0.56
- 2.0.57
- 2.0.58
- 2.0.59
- 2.0.60
- 2.0.61
- 2.0.63
- 2.0.64
Configuration 2
- 2.2.0
- 2.2.1
- 2.2.2
- 2.2.3
- 2.2.4
- 2.2.6
- 2.2.8
- 2.2.9
- 2.2.10
- 2.2.11
- 2.2.12
- 2.2.13
- 2.2.14
- 2.2.15
- 2.2.16
- 2.2.18
- 2.2.19
- 2.2.20
- 2.2.21
No data.
Red Hat Directory Server 8
httpd
Will not fix
Red Hat Enterprise Linux 4
httpd
Will not fix
Red Hat Enterprise Linux 5
httpd
Will not fix
Red Hat Enterprise Linux 6
httpd
Will not fix
Red Hat JBoss Enterprise Web Server 1
httpd
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Directory Server 8 | httpd | Will not fix | n/a |
| Red Hat Enterprise Linux 4 | httpd | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | httpd | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | httpd | Will not fix | n/a |
| Red Hat JBoss Enterprise Web Server 1 | httpd | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
The ASF Security Team does not consider resource exhaustion caused by .htaccess files to be a security defect. The Red Hat Security Response Team agrees with their assessment and so does not consider this to be a security flaw.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
AV:L/AC:H/Au:N/C:N/I:N/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (9 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 3.02% (0.03019) | 86.99th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.28% (0.03281) | 86.79th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.61% (0.00613) | 68.01th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.04% (0.00042) | 5.07th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.04% (0.00042) | 5.63th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.16% (0.01164) | 61.38th | v2 (v2022.01.01) |
| Oct 18, 2022 | 1.16% (0.01164) | 60.38th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.16% (0.01164) | 58.38th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.16% (0.01164) | 34.94th | v2 (v2022.01.01) |
References (8)
- http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c03360041 vendor-advisoryx_refsource_HP
- http://www.gossamer-threads.com/lists/apache/dev/403775 x_refsource_CONFIRM
- http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/ x_refsource_MISCExploitPatch
- http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/DemoExploit.html x_refsource_MISCExploit
- https://access.redhat.com/security/cve/CVE-2011-4415 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=750935 Issue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2011-4415
- https://www.cve.org/CVERecord?id=CVE-2011-4415
| Link | Providers | Tags |
|---|---|---|
| http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c03360041 | vendor-advisoryx_refsource_HP | |
| http://www.gossamer-threads.com/lists/apache/dev/403775 | x_refsource_CONFIRM | |
| http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/ | x_refsource_MISCExploitPatch | |
| http://www.halfdog.net/Security/2011/ApacheModSetEnvIfIntegerOverflow/DemoExploit.html | x_refsource_MISCExploit | |
| https://access.redhat.com/security/cve/CVE-2011-4415 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=750935 | Issue Tracking | |
| https://nvd.nist.gov/vuln/detail/CVE-2011-4415 | ||
| https://www.cve.org/CVERecord?id=CVE-2011-4415 |
Change history (0)
No recorded changes yet.