CVE-2013-1055 | Potential DoS through abuse of rate limit in libunity-webapps for Firefox

Exp

The unity-firefox-extension package could be tricked into dropping a C callback which was still in use, which Firefox would then free, causing Firefox to crash. This could be achieved by adding an action to the launcher and updating it with new callbacks until the libunity-webapps rate limit was hit. Fixed in 3.0.0+14.04.20140416-0ubuntu1.14.04.1 of unity-firefox-extension and in all versions of libunity-webapps by shipping an empty unity-firefox-extension package, thus disabling the extension entirely and invalidating the attack against the libunity-webapps package.

Published: 2021-04-07 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2013-1055 is rated Exploit Available (56.4/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.27%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.09% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2013-1055

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2013-1055

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.19% 1.27% +1.09%
2 2026-01-09 0.34% 0.19% -0.15%
3 2025-10-05 — 0.34% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2013-1055

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.8 1.4 [email protected]
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.8 1.4 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2013-1055

OS Trackers for CVE-2013-1055

vendor priority summary link
ubuntu low CVE-2013-1055 low priority: Ubuntu including 1 source packages (unity-firefox-extension), 9 status rows across 9 suites (lucid, precise, quantal, raring, saucy, trusty, upstream, vivid, wily): DNE 3, ignored 3, released 2, needs-triage 1. https://ubuntu.com/security/CVE-2013-1055

Affected software / configurations for CVE-2013-1055

Vendor Product Version Raw CPE
canonical unity-firefox-extension < 3.0.0\+14.04.20140416-0ubuntu1.14.04.1 cpe:2.3:a:canonical:unity-firefox-extension:*:*:*:*:*:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 15.04 cpe:2.3:o:canonical:ubuntu_linux:15.04:*:*:*:*:*:*:*

References for CVE-2013-1055

URL Tags
https://launchpad.net/bugs/1175691 Exploit Vendor Advisory
https://ubuntu.com/USN-2743-3 Vendor Advisory
cvelogic Threat Intelligence