libevent: multiple integer overflows in the evbuffer APIs
Published Aug 24, 2015
7.5
HIGHCVSS 2.0
EPSS 4.81%
Description
Multiple integer overflows in the evbuffer API in Libevent 2.0.x before 2.0.22 and 2.1.x before 2.1.5-beta allow context-dependent attackers to cause a denial of service or possibly have other unspecified impact via "insanely large inputs" to the (1) evbuffer_add, (2) evbuffer_prepend, (3) evbuffer_expand, (4) exbuffer_reserve_space, or (5) evbuffer_read function, which triggers a heap-based buffer overflow or an infinite loop. NOTE: this identifier was SPLIT from CVE-2014-6272 per ADT3 due to different affected versions.
Affected products
No data.
Configuration 1
- 7.1
Configuration 2
- 2.0.1
- 2.0.2
- 2.0.3
- 2.0.4
- 2.0.5
- 2.0.6
- 2.0.7
- 2.0.8
- 2.0.9
- 2.0.10
- 2.0.11
- 2.0.12
- 2.0.13
- 2.0.14
- 2.0.15
- 2.0.16
- 2.0.17
- 2.0.18
- 2.0.19
- 2.0.20
- 2.0.21
- 2.1.1
- 2.1.2
- 2.1.3
- 2.1.4
No data.
Red Hat Enterprise Linux 4
nfs-utils
Not affected
Red Hat Enterprise Linux 4
openmpi
Not affected
Red Hat Enterprise Linux 5
firefox
Will not fix
Red Hat Enterprise Linux 5
libevent
Not affected
Red Hat Enterprise Linux 5
openmpi
Not affected
Red Hat Enterprise Linux 5
thunderbird
Will not fix
Red Hat Enterprise Linux 6
chromium-browser
Will not fix
Red Hat Enterprise Linux 6
firefox
Will not fix
Red Hat Enterprise Linux 6
libevent
Not affected
Red Hat Enterprise Linux 6
openmpi
Not affected
Red Hat Enterprise Linux 6
thunderbird
Will not fix
Red Hat Enterprise Linux 7
firefox
Will not fix
Red Hat Enterprise Linux 7
libevent
Will not fix
Red Hat Enterprise Linux 7
openmpi
Not affected
Red Hat Enterprise Linux 7
thunderbird
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 4 | nfs-utils | Not affected | n/a |
| Red Hat Enterprise Linux 4 | openmpi | Not affected | n/a |
| Red Hat Enterprise Linux 5 | firefox | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | libevent | Not affected | n/a |
| Red Hat Enterprise Linux 5 | openmpi | Not affected | n/a |
| Red Hat Enterprise Linux 5 | thunderbird | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | chromium-browser | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | firefox | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | libevent | Not affected | n/a |
| Red Hat Enterprise Linux 6 | openmpi | Not affected | n/a |
| Red Hat Enterprise Linux 6 | thunderbird | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | firefox | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | libevent | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | openmpi | Not affected | n/a |
| Red Hat Enterprise Linux 7 | thunderbird | Will not fix | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
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:N/AC:L/Au:N/C:P/I:P/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 1, 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 (12 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 4.81% (0.04813) | 91.69th | v5 (v2026.06.15) |
| Jun 15, 2026 | 4.81% (0.04813) | 90.80th | v5 (v2026.06.15) |
| Mar 30, 2025 | 1.07% (0.01070) | 75.75th | v4 (v2025.03.14) |
| Mar 29, 2025 | 2.33% (0.02331) | 74.73th | v4 (v2025.03.14) |
| Mar 17, 2025 | 1.07% (0.01070) | 76.20th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.21% (0.00211) | 59.93th | v3 (v2023.03.01) |
| Jun 13, 2024 | 0.21% (0.00211) | 59.17th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.21% (0.00211) | 57.15th | v3 (v2023.03.01) |
| Mar 6, 2023 | 0.89% (0.00885) | 27.89th | v2 (v2022.01.01) |
| Sep 10, 2022 | 0.89% (0.00885) | 26.24th | v2 (v2022.01.01) |
| Apr 1, 2022 | 0.89% (0.00885) | 24.24th | v2 (v2022.01.01) |
| Feb 4, 2022 | 0.89% (0.00885) | 10.50th | v2 (v2022.01.01) |
References (6)
- http://archives.seul.org/libevent/users/Jan-2015/msg00010.html mailing-listx_refsource_MLISTVendor Advisory
- http://www.debian.org/security/2015/dsa-3119 vendor-advisoryx_refsource_DEBIAN
- https://access.redhat.com/security/cve/CVE-2015-6525 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1256797 Issue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2015-6525
- https://www.cve.org/CVERecord?id=CVE-2015-6525
| Link | Providers | Tags |
|---|---|---|
| http://archives.seul.org/libevent/users/Jan-2015/msg00010.html | mailing-listx_refsource_MLISTVendor Advisory | |
| http://www.debian.org/security/2015/dsa-3119 | vendor-advisoryx_refsource_DEBIAN | |
| https://access.redhat.com/security/cve/CVE-2015-6525 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1256797 | Issue Tracking | |
| https://nvd.nist.gov/vuln/detail/CVE-2015-6525 | ||
| https://www.cve.org/CVERecord?id=CVE-2015-6525 |
Change history (0)
No recorded changes yet.